diff --git a/package.json b/package.json
index d30587d3..4d375e7c 100644
--- a/package.json
+++ b/package.json
@@ -32,7 +32,7 @@
 		"website:build:css": "cp ./node_modules/minireset.css/minireset.min.css ./website/styles/",
 		"website:build:ts": "tsc --project ./website",
 		"test": "run-s test:*",
-		"test:jest": "cross-env TZ=GMT jest",
+		"test:jest": "jest",
 		"test:types": "tsc --noEmit && tsc --project ./website --noEmit",
 		"lint:css": "stylelint --fix --ignore-path ./.gitignore --max-warnings 0 '**/*.{css,sass,scss}'",
 		"lint:ts": "eslint --ext .ts,.tsx --fix --ignore-path ./.gitignore --max-warnings 0 '**/*.{ts,tsx}'",
@@ -98,7 +98,6 @@
 		"@typescript-eslint/eslint-plugin": "^2.26.0",
 		"@typescript-eslint/parser": "^2.26.0",
 		"babel-loader": "^8.1.0",
-		"cross-env": "^7.0.2",
 		"css-loader": "^3.4.0",
 		"electron": "^8.2.0",
 		"electron-builder": "^22.4.1",
diff --git a/src/renderer/components/elements/editor/editor-toolbar/word-count/WordCount.tsx b/src/renderer/components/elements/editor/editor-toolbar/word-count/WordCount.tsx
index 94bc7175..4f74c12c 100644
--- a/src/renderer/components/elements/editor/editor-toolbar/word-count/WordCount.tsx
+++ b/src/renderer/components/elements/editor/editor-toolbar/word-count/WordCount.tsx
@@ -1,3 +1,4 @@
+import { Moment } from "moment";
 import React, { ReactElement } from "react";
 import countWords from "word-count";
 
@@ -5,7 +6,7 @@ import { Entries } from "../../../../../types";
 import { toIndexDate } from "../../../../../utils/dateFormat";
 
 export interface StateProps {
-	dateSelected: Date;
+	dateSelected: Moment;
 	entries: Entries;
 }
 
diff --git a/src/renderer/components/elements/editor/editor/Editor.tsx b/src/renderer/components/elements/editor/editor/Editor.tsx
index 901aa0d6..ba86bd58 100644
--- a/src/renderer/components/elements/editor/editor/Editor.tsx
+++ b/src/renderer/components/elements/editor/editor/Editor.tsx
@@ -14,6 +14,7 @@ import createListPlugin from "draft-js-list-plugin";
 import PluginEditor from "draft-js-plugins-editor";
 import debounce from "lodash.debounce";
 import { draftToMarkdown, markdownToDraft } from "markdown-draft-js";
+import { Moment } from "moment";
 import React, { KeyboardEvent, PureComponent, ReactNode } from "react";
 
 import { Entries, IndexDate } from "../../../../types";
@@ -30,7 +31,7 @@ const listPlugin = createListPlugin();
 const plugins = [listPlugin];
 
 export interface StateProps {
-	dateSelected: Date;
+	dateSelected: Moment;
 	entries: Entries;
 }
 
@@ -41,7 +42,7 @@ export interface DispatchProps {
 type Props = StateProps & DispatchProps;
 
 interface State {
-	dateSelected: Date;
+	dateSelected: Moment;
 	textEditorState: EditorState;
 	titleEditorState: EditorState;
 }
@@ -63,7 +64,7 @@ export default class Editor extends PureComponent<Props, State> {
 
 	static getStateFromEntry(
 		entries: Entries,
-		date: Date,
+		date: Moment,
 	): { textEditorState: EditorState; titleEditorState: EditorState } {
 		const indexDate = toIndexDate(date);
 		const entry = entries[indexDate];
diff --git a/src/renderer/components/elements/sidebar/calendar-nav/CalendarNav.tsx b/src/renderer/components/elements/sidebar/calendar-nav/CalendarNav.tsx
index 8a28a750..07ed173b 100644
--- a/src/renderer/components/elements/sidebar/calendar-nav/CalendarNav.tsx
+++ b/src/renderer/components/elements/sidebar/calendar-nav/CalendarNav.tsx
@@ -1,16 +1,16 @@
 import PrevIcon from "feather-icons/dist/icons/chevron-left.svg";
 import NextIcon from "feather-icons/dist/icons/chevron-right.svg";
-import moment from "moment";
+import { Moment } from "moment";
 import React, { ReactElement } from "react";
 
 import { MAX_DATE, MIN_DATE } from "../../../../constants";
-import { toMonthYear } from "../../../../utils/dateFormat";
+import { createDate, parseDate, toMonthYear } from "../../../../utils/dateFormat";
 import { translations } from "../../../../utils/i18n";
 import { iconProps } from "../../../../utils/icons";
 
 export interface StateProps {
 	allowFutureEntries: boolean;
-	monthSelected: Date;
+	monthSelected: Moment;
 }
 
 export interface DispatchProps {
@@ -28,11 +28,11 @@ export default function CalendarNav(props: Props): ReactElement {
 		setMonthSelectedPrevious,
 	} = props;
 
-	const today = moment();
+	const today = createDate();
 
 	// Check if buttons for switching to previous/next month should be enabled. Determined based on
 	// the min/max dates and whether future diary entries are allowed
-	const month = moment(monthSelected);
+	const month = parseDate(monthSelected);
 	const canClickPrev = month.isAfter(MIN_DATE, "month");
 	const canClickNext =
 		month.isBefore(MAX_DATE, "month") && (allowFutureEntries || month.isBefore(today, "month"));
diff --git a/src/renderer/components/elements/sidebar/calendar/Calendar.tsx b/src/renderer/components/elements/sidebar/calendar/Calendar.tsx
index 3f238935..b75696c7 100644
--- a/src/renderer/components/elements/sidebar/calendar/Calendar.tsx
+++ b/src/renderer/components/elements/sidebar/calendar/Calendar.tsx
@@ -1,23 +1,23 @@
-import moment from "moment";
+import { Moment } from "moment";
 import React, { PureComponent, ReactNode } from "react";
 import DayPicker from "react-day-picker";
 import MomentLocaleUtils from "react-day-picker/moment";
 
 import { Entries, Weekday } from "../../../../types";
-import { toIndexDate } from "../../../../utils/dateFormat";
+import { createDate, parseDate, toIndexDate } from "../../../../utils/dateFormat";
 import { lang } from "../../../../utils/i18n";
 import CalendarNavContainer from "../calendar-nav/CalendarNavContainer";
 
 export interface StateProps {
 	allowFutureEntries: boolean;
-	dateSelected: Date;
+	dateSelected: Moment;
 	entries: Entries;
 	firstDayOfWeek: Weekday | null;
-	monthSelected: Date;
+	monthSelected: Moment;
 }
 
 export interface DispatchProps {
-	setDateSelected: (date: Date) => void;
+	setDateSelected: (date: Moment) => void;
 }
 
 type Props = StateProps & DispatchProps;
@@ -32,28 +32,31 @@ export default class Calendar extends PureComponent<Props, {}> {
 
 	onDateSelection(date: Date): void {
 		const { allowFutureEntries, setDateSelected } = this.props;
+		const parsedDate = parseDate(date);
+		const today = createDate();
 
-		if (allowFutureEntries || moment(date).isSameOrBefore(moment(), "day")) {
-			setDateSelected(date);
+		if (allowFutureEntries || parseDate(date).isSameOrBefore(today, "day")) {
+			setDateSelected(parsedDate);
 		}
 	}
 
 	render(): ReactNode {
 		const { allowFutureEntries, dateSelected, entries, firstDayOfWeek, monthSelected } = this.props;
 
-		const today = new Date();
+		const today = createDate();
 		const daysWithEntries = Object.keys(entries);
-		const hasEntry = (day: Date): boolean => {
-			const indexDate = toIndexDate(day);
+
+		const hasEntry = (date: Date): boolean => {
+			const indexDate = toIndexDate(parseDate(date));
 			return daysWithEntries.includes(indexDate);
 		};
 
 		return (
 			<DayPicker
-				selectedDays={dateSelected}
-				disabledDays={allowFutureEntries ? null : { after: today }}
-				month={monthSelected}
-				toMonth={today}
+				selectedDays={dateSelected.toDate()}
+				disabledDays={allowFutureEntries ? null : { after: today.toDate() }}
+				month={monthSelected.toDate()}
+				toMonth={today.toDate()}
 				captionElement={(): null => null}
 				modifiers={{ hasEntry }}
 				firstDayOfWeek={firstDayOfWeek ?? undefined}
diff --git a/src/renderer/components/elements/sidebar/calendar/CalendarContainer.tsx b/src/renderer/components/elements/sidebar/calendar/CalendarContainer.tsx
index ddeef8fc..db38071c 100644
--- a/src/renderer/components/elements/sidebar/calendar/CalendarContainer.tsx
+++ b/src/renderer/components/elements/sidebar/calendar/CalendarContainer.tsx
@@ -1,3 +1,4 @@
+import { Moment } from "moment";
 import { connect } from "react-redux";
 
 import { setDateSelected } from "../../../../store/diary/actionCreators";
@@ -14,7 +15,7 @@ const mapStateToProps = (state: RootState): StateProps => ({
 });
 
 const mapDispatchToProps = (dispatch: ThunkDispatchT): DispatchProps => ({
-	setDateSelected: (date: Date): SetDateSelectedAction => dispatch(setDateSelected(date)),
+	setDateSelected: (date: Moment): SetDateSelectedAction => dispatch(setDateSelected(date)),
 });
 
 export default connect(mapStateToProps, mapDispatchToProps)(Calendar);
diff --git a/src/renderer/components/elements/sidebar/search-bar/SearchBar.tsx b/src/renderer/components/elements/sidebar/search-bar/SearchBar.tsx
index bd809839..1ad28ea9 100644
--- a/src/renderer/components/elements/sidebar/search-bar/SearchBar.tsx
+++ b/src/renderer/components/elements/sidebar/search-bar/SearchBar.tsx
@@ -1,21 +1,22 @@
 import ClearIcon from "feather-icons/dist/icons/x.svg";
 import debounce from "lodash.debounce";
-import moment from "moment";
+import { Moment } from "moment";
 import React, { ChangeEvent, PureComponent, ReactNode } from "react";
 
 import TodayIcon from "../../../../assets/icons/today.svg";
+import { createDate, parseDate } from "../../../../utils/dateFormat";
 import { translations } from "../../../../utils/i18n";
 import { iconProps } from "../../../../utils/icons";
 
 export interface StateProps {
-	dateSelected: Date;
-	monthSelected: Date;
+	dateSelected: Moment;
+	monthSelected: Moment;
 	searchKey: string;
 }
 
 export interface DispatchProps {
 	search: (searchKey: string) => void;
-	setDateSelected: (date: Date) => void;
+	setDateSelected: (date: Moment) => void;
 }
 
 type Props = StateProps & DispatchProps;
@@ -56,7 +57,7 @@ export default class SearchBar extends PureComponent<Props, State> {
 	onTodaySelection(): void {
 		const { setDateSelected } = this.props;
 
-		const today = new Date();
+		const today = createDate();
 		setDateSelected(today);
 	}
 
@@ -77,9 +78,9 @@ export default class SearchBar extends PureComponent<Props, State> {
 		const { dateSelected, monthSelected } = this.props;
 		const { newSearchKey } = this.state;
 
-		const today = moment();
-		const isToday = moment(dateSelected).isSame(today, "day");
-		const isCurrentMonth = moment(monthSelected).isSame(today, "month");
+		const today = createDate();
+		const isToday = parseDate(dateSelected).isSame(today, "day");
+		const isCurrentMonth = parseDate(monthSelected).isSame(today, "month");
 
 		return (
 			<div className="view-selector">
diff --git a/src/renderer/components/elements/sidebar/search-bar/SearchBarContainer.tsx b/src/renderer/components/elements/sidebar/search-bar/SearchBarContainer.tsx
index 2c06ebf8..fb9336f2 100644
--- a/src/renderer/components/elements/sidebar/search-bar/SearchBarContainer.tsx
+++ b/src/renderer/components/elements/sidebar/search-bar/SearchBarContainer.tsx
@@ -1,3 +1,4 @@
+import { Moment } from "moment";
 import { connect } from "react-redux";
 
 import { search, setDateSelected } from "../../../../store/diary/actionCreators";
@@ -13,7 +14,7 @@ const mapStateToProps = (state: RootState): StateProps => ({
 
 const mapDispatchToProps = (dispatch: ThunkDispatchT): DispatchProps => ({
 	search: (searchKey: string): void => dispatch(search(searchKey)),
-	setDateSelected: (date: Date): SetDateSelectedAction => dispatch(setDateSelected(date)),
+	setDateSelected: (date: Moment): SetDateSelectedAction => dispatch(setDateSelected(date)),
 });
 
 export default connect(mapStateToProps, mapDispatchToProps)(SearchBar);
diff --git a/src/renderer/components/elements/sidebar/search-results/SearchResults.tsx b/src/renderer/components/elements/sidebar/search-results/SearchResults.tsx
index 58602a63..2cffcc7a 100644
--- a/src/renderer/components/elements/sidebar/search-results/SearchResults.tsx
+++ b/src/renderer/components/elements/sidebar/search-results/SearchResults.tsx
@@ -1,18 +1,19 @@
+import { Moment } from "moment";
 import React, { PureComponent, ReactNode } from "react";
 
 import { Entries } from "../../../../types";
-import { momentIndex, toDateString } from "../../../../utils/dateFormat";
+import { fromIndexDate, toDateString } from "../../../../utils/dateFormat";
 import { translations } from "../../../../utils/i18n";
 import Banner from "../../general/banner/Banner";
 
 export interface StateProps {
-	dateSelected: Date;
+	dateSelected: Moment;
 	entries: Entries;
 	searchResults: string[];
 }
 
 export interface DispatchProps {
-	setDateSelected: (date: Date) => void;
+	setDateSelected: (date: Moment) => void;
 }
 
 type Props = StateProps & DispatchProps;
@@ -36,7 +37,7 @@ export default class SearchResults extends PureComponent<Props, {}> {
 				// Create search result element if a corresponding diary entry exists
 				// (When deleting a diary entry after a search, it is still part of the search results
 				// until a new search is performed. That's why it needs to be filtered out here)
-				const date = momentIndex(searchResult);
+				const date = fromIndexDate(searchResult);
 				const { title } = entries[searchResult];
 				const isSelected = date.isSame(dateSelected, "day");
 				r.push(
@@ -44,7 +45,7 @@ export default class SearchResults extends PureComponent<Props, {}> {
 						<button
 							type="button"
 							className={`button ${isSelected ? "button-main" : ""}`}
-							onClick={(): void => setDateSelected(date.toDate())}
+							onClick={(): void => setDateSelected(date)}
 						>
 							<p className="search-date text-faded">{toDateString(date)}</p>
 							<p className={`search-title ${!title ? "text-faded" : ""}`}>
diff --git a/src/renderer/components/elements/sidebar/search-results/SearchResultsContainer.tsx b/src/renderer/components/elements/sidebar/search-results/SearchResultsContainer.tsx
index 03a12712..846bef31 100644
--- a/src/renderer/components/elements/sidebar/search-results/SearchResultsContainer.tsx
+++ b/src/renderer/components/elements/sidebar/search-results/SearchResultsContainer.tsx
@@ -1,3 +1,4 @@
+import { Moment } from "moment";
 import { connect } from "react-redux";
 
 import { setDateSelected } from "../../../../store/diary/actionCreators";
@@ -12,7 +13,7 @@ const mapStateToProps = (state: RootState): StateProps => ({
 });
 
 const mapDispatchToProps = (dispatch: ThunkDispatchT): DispatchProps => ({
-	setDateSelected: (date: Date): SetDateSelectedAction => dispatch(setDateSelected(date)),
+	setDateSelected: (date: Moment): SetDateSelectedAction => dispatch(setDateSelected(date)),
 });
 
 export default connect(mapStateToProps, mapDispatchToProps)(SearchResults);
diff --git a/src/renderer/components/overlays/go-to-date-overlay/GoToDateOverlay.tsx b/src/renderer/components/overlays/go-to-date-overlay/GoToDateOverlay.tsx
index f973df9a..26780fbb 100644
--- a/src/renderer/components/overlays/go-to-date-overlay/GoToDateOverlay.tsx
+++ b/src/renderer/components/overlays/go-to-date-overlay/GoToDateOverlay.tsx
@@ -1,18 +1,19 @@
 import logger from "electron-log";
+import { Moment } from "moment";
 import React, { ChangeEvent, FormEvent, ReactElement, useState } from "react";
 
-import { momentIndex, toIndexDate } from "../../../utils/dateFormat";
+import { createDate, fromIndexDate, toIndexDate } from "../../../utils/dateFormat";
 import { translations } from "../../../utils/i18n";
 import OverlayContainer from "../overlay-hoc/OverlayContainer";
 
 export interface StateProps {
 	allowFutureEntries: boolean;
-	dateSelected: Date;
+	dateSelected: Moment;
 }
 
 export interface DispatchProps {
 	closeOverlay: () => void;
-	setDateSelected: (date: Date) => void;
+	setDateSelected: (date: Moment) => void;
 }
 
 type Props = StateProps & DispatchProps;
@@ -23,7 +24,7 @@ type Props = StateProps & DispatchProps;
 export default function GoToDateOverlay(props: Props): ReactElement {
 	const { allowFutureEntries, closeOverlay, dateSelected, setDateSelected } = props;
 
-	const todayFormatted = toIndexDate(new Date());
+	const todayFormatted = toIndexDate(createDate());
 	const dateSelectedFormatted = toIndexDate(dateSelected);
 
 	// `date` can become `undefined` when the user's date input is incomplete (e.g. year not filled in
@@ -37,7 +38,7 @@ export default function GoToDateOverlay(props: Props): ReactElement {
 		if (!date) {
 			logger.error("Cannot go to date: Date is not defined");
 		} else {
-			setDateSelected(momentIndex(date).toDate());
+			setDateSelected(fromIndexDate(date));
 			closeOverlay();
 		}
 	};
diff --git a/src/renderer/components/overlays/go-to-date-overlay/GoToDateOverlayContainer.tsx b/src/renderer/components/overlays/go-to-date-overlay/GoToDateOverlayContainer.tsx
index 7f345780..cea24928 100644
--- a/src/renderer/components/overlays/go-to-date-overlay/GoToDateOverlayContainer.tsx
+++ b/src/renderer/components/overlays/go-to-date-overlay/GoToDateOverlayContainer.tsx
@@ -1,3 +1,4 @@
+import { Moment } from "moment";
 import { connect } from "react-redux";
 
 import { closeOverlay } from "../../../store/app/actionCreators";
@@ -14,7 +15,7 @@ const mapStateToProps = (state: RootState): StateProps => ({
 
 const mapDispatchToProps = (dispatch: ThunkDispatchT): DispatchProps => ({
 	closeOverlay: (): SetOverlayAction => dispatch(closeOverlay()),
-	setDateSelected: (date: Date): SetDateSelectedAction => dispatch(setDateSelected(date)),
+	setDateSelected: (date: Moment): SetDateSelectedAction => dispatch(setDateSelected(date)),
 });
 
 export default connect(mapStateToProps, mapDispatchToProps)(GoToDateOverlay);
diff --git a/src/renderer/components/overlays/stats-overlay/StatsOverlay.tsx b/src/renderer/components/overlays/stats-overlay/StatsOverlay.tsx
index 0d1172be..fb184c49 100644
--- a/src/renderer/components/overlays/stats-overlay/StatsOverlay.tsx
+++ b/src/renderer/components/overlays/stats-overlay/StatsOverlay.tsx
@@ -1,10 +1,9 @@
-import moment from "moment";
 import React, { PureComponent, ReactNode } from "react";
 import countWords from "word-count";
 
 import { getLang } from "../../../electron/ipcRenderer/senders";
 import { Entries } from "../../../types";
-import { momentIndex } from "../../../utils/dateFormat";
+import { createDate, fromIndexDate } from "../../../utils/dateFormat";
 import { translations } from "../../../utils/i18n";
 import OverlayContainer from "../overlay-hoc/OverlayContainer";
 
@@ -40,19 +39,19 @@ export default class StatsOverlay extends PureComponent<Props, {}> {
 	static calcStats(entries: Entries): Stats {
 		const indexDatesSorted = Object.keys(entries).sort();
 		const nrEntries = indexDatesSorted.length;
-		const today = moment();
+		const today = createDate();
 
 		let currentStreak = 1;
 		let longestStreak = 0;
 		let nrWords = 0;
-		let prevDate = momentIndex("1970/01/01");
+		let prevDate = fromIndexDate("1970/01/01");
 
 		// Loop over sorted indices and find corresponding diary entry. Update stats variables using its
 		// content
 		indexDatesSorted.forEach((indexDate): void => {
 			const entry = entries[indexDate];
 			const { title, text } = entry;
-			const date = momentIndex(indexDate);
+			const date = fromIndexDate(indexDate);
 
 			// Check if the current date is one day after the previous one. If so, increase
 			// `currentStreak`. If not, update `longestStreak` if necessary and reset `currentStreak`
diff --git a/src/renderer/constants.ts b/src/renderer/constants.ts
index 944e57b9..a8941b4a 100644
--- a/src/renderer/constants.ts
+++ b/src/renderer/constants.ts
@@ -1,4 +1,6 @@
+import { parseDate } from "./utils/dateFormat";
+
 // Dates
 
-export const MIN_DATE = new Date(1900, 0, 1);
-export const MAX_DATE = new Date(2099, 11, 31);
+export const MIN_DATE = parseDate("1900-01-01");
+export const MAX_DATE = parseDate("2099-12-31");
diff --git a/src/renderer/files/diary/backupFile.ts b/src/renderer/files/diary/backupFile.ts
index 70822e79..2404779f 100644
--- a/src/renderer/files/diary/backupFile.ts
+++ b/src/renderer/files/diary/backupFile.ts
@@ -2,7 +2,7 @@ import { remote } from "electron";
 import fs from "fs";
 import path from "path";
 
-import { toFilenameDate } from "../../utils/dateFormat";
+import { createDate, toFileNameDate } from "../../utils/dateFormat";
 import { copyFile } from "../fileAccess";
 import { getDiaryFilePath } from "./diaryFile";
 
@@ -23,7 +23,7 @@ function createBackupDir(dir: string): void {
  * Create a backup of the diary by copying the diary file to the backup directory
  */
 function createBackupFile(dir: string): void {
-	const dateTime = toFilenameDate(new Date());
+	const dateTime = toFileNameDate(createDate());
 	const diaryFilePath = getDiaryFilePath();
 	const backupPath = path.join(dir, `backup-${dateTime}.txt`);
 	copyFile(diaryFilePath, backupPath);
diff --git a/src/renderer/files/diary/diaryFile.ts b/src/renderer/files/diary/diaryFile.ts
index 304f11ec..15a62179 100644
--- a/src/renderer/files/diary/diaryFile.ts
+++ b/src/renderer/files/diary/diaryFile.ts
@@ -2,6 +2,7 @@ import { remote } from "electron";
 import path from "path";
 
 import { Metadata } from "../../types";
+import { createDate } from "../../utils/dateFormat";
 import { loadDirPref } from "../preferences/preferences";
 
 export const FILE_NAME = "mini-diary.txt";
@@ -26,6 +27,6 @@ export function getDiaryFilePath(): string {
 export function getMetadata(): Metadata {
 	return {
 		...METADATA,
-		dateUpdated: new Date().toString(),
+		dateUpdated: createDate().toString(),
 	};
 }
diff --git a/src/renderer/files/export/md.ts b/src/renderer/files/export/md.ts
index d1bc3168..c040fb91 100644
--- a/src/renderer/files/export/md.ts
+++ b/src/renderer/files/export/md.ts
@@ -1,5 +1,5 @@
 import { Entries } from "../../types";
-import { momentIndex, toLocaleWeekday } from "../../utils/dateFormat";
+import { fromIndexDate, toLocaleWeekday } from "../../utils/dateFormat";
 import sortEntries from "./sortEntries";
 
 /**
@@ -22,7 +22,7 @@ export function convertToMd(entries: Entries): Promise<string> {
 			const { text, title } = entry;
 
 			// Format date
-			const dateStr = toLocaleWeekday(momentIndex(indexDate));
+			const dateStr = toLocaleWeekday(fromIndexDate(indexDate));
 
 			// Build Markdown string
 			md += `## ${dateStr}\n\n`; // Date
diff --git a/src/renderer/files/export/txt.ts b/src/renderer/files/export/txt.ts
index 2b486f88..cc645748 100644
--- a/src/renderer/files/export/txt.ts
+++ b/src/renderer/files/export/txt.ts
@@ -1,5 +1,5 @@
 import { Entries } from "../../types";
-import { momentIndex, toDayOneDate } from "../../utils/dateFormat";
+import { fromIndexDate, toDayOneDate } from "../../utils/dateFormat";
 import mdToTxt from "../../utils/mdToTxt";
 import sortEntries from "./sortEntries";
 
@@ -21,7 +21,7 @@ export async function convertToDayOneTxt(entries: Entries): Promise<string> {
 		const { text, title } = entry;
 
 		// Format date
-		const dayOneDate = toDayOneDate(momentIndex(indexDate));
+		const dayOneDate = toDayOneDate(fromIndexDate(indexDate));
 
 		// Build TXT string
 		txt += `\tDate:\t${dayOneDate}\n\n`; // Date
diff --git a/src/renderer/files/import/json.ts b/src/renderer/files/import/json.ts
index 2280a42c..df9e843c 100644
--- a/src/renderer/files/import/json.ts
+++ b/src/renderer/files/import/json.ts
@@ -1,15 +1,15 @@
 import {
-	Entries,
+	DayOneEntry,
 	DayOneJson,
-	ImportEntry,
 	DiaryEntry,
-	DayOneEntry,
-	JrnlJson,
+	Entries,
+	ImportEntry,
 	JrnlEntry,
-	MiniDiaryJson,
+	JrnlJson,
 	ListDiaryEntry,
+	MiniDiaryJson,
 } from "../../types";
-import { toIndexDate } from "../../utils/dateFormat";
+import { createDate, parseDate, toIndexDate } from "../../utils/dateFormat";
 import buildEntries from "./buildEntries";
 
 /**
@@ -24,8 +24,8 @@ export function parseDayOneJson(jsonStr: string): Entries {
 	} => {
 		const parsedEntryCast = parsedEntry as DayOneEntry;
 		const { creationDate, modifiedDate, text: titleAndText } = parsedEntryCast;
-		const indexDate = toIndexDate(new Date(creationDate));
-		const dateUpdated = new Date(modifiedDate).toString();
+		const indexDate = toIndexDate(creationDate);
+		const dateUpdated = parseDate(modifiedDate).toString();
 
 		// Split title and text (if exists)
 		let title;
@@ -54,7 +54,7 @@ export function parseDayOneJson(jsonStr: string): Entries {
  */
 export function parseJrnlJson(jsonStr: string): Entries {
 	const parsedEntries: JrnlJson = JSON.parse(jsonStr);
-	const now = new Date().toString();
+	const now = createDate().toString();
 
 	return buildEntries(parsedEntries.entries, (parsedEntry: ImportEntry): {
 		indexDate: string;
@@ -62,7 +62,7 @@ export function parseJrnlJson(jsonStr: string): Entries {
 	} => {
 		const parsedEntryCast = parsedEntry as JrnlEntry;
 		const { date, title, body } = parsedEntryCast;
-		const indexDate = toIndexDate(new Date(date));
+		const indexDate = toIndexDate(date);
 
 		const entry = { dateUpdated: now, title: title.trim(), text: body.trim() };
 		return { indexDate, entry };
@@ -77,7 +77,7 @@ export function parseMiniDiaryJson(jsonStr: string): Entries {
 	const parsedEntries = Object.entries(parsedJson.entries).map(
 		([indexDate, entry]): ListDiaryEntry => ({ ...entry, indexDate }),
 	);
-	const now = new Date().toString();
+	const now = createDate().toString();
 
 	return buildEntries(parsedEntries, (parsedEntry: ImportEntry): {
 		indexDate: string;
@@ -87,10 +87,8 @@ export function parseMiniDiaryJson(jsonStr: string): Entries {
 		const { indexDate, text, title } = parsedEntryCast;
 
 		// Use dateUpdated if defined, otherwise set it to now
-		let dateUpdated;
-		if ("dateUpdated" in parsedEntryCast) {
-			dateUpdated = new Date(parsedEntryCast.dateUpdated).toString();
-		} else {
+		let { dateUpdated } = parsedEntryCast;
+		if (!("dateUpdated" in parsedEntryCast)) {
 			dateUpdated = now;
 		}
 
diff --git a/src/renderer/files/import/txt.ts b/src/renderer/files/import/txt.ts
index bee843fe..f417c122 100644
--- a/src/renderer/files/import/txt.ts
+++ b/src/renderer/files/import/txt.ts
@@ -1,14 +1,12 @@
-import moment from "moment";
-
-import { Entries, ImportEntry, DiaryEntry } from "../../types";
-import { toIndexDate } from "../../utils/dateFormat";
+import { DiaryEntry, Entries, ImportEntry } from "../../types";
+import { createDate, parseDate, toIndexDate } from "../../utils/dateFormat";
 import buildEntries from "./buildEntries";
 
 /**
  * Parse the TXT file generated by a Day One export and format it as an Entries object
  */
 export function parseDayOneTxt(dayOneTxt: string): Entries {
-	const now = new Date().toString();
+	const now = createDate().toString();
 
 	// Split up diary entries and filter out empty ones
 	const parsedEntries = dayOneTxt.split("\tDate:\t").filter((entry): string => entry);
@@ -24,7 +22,7 @@ export function parseDayOneTxt(dayOneTxt: string): Entries {
 
 		// Parse date (format "01 January 1980 at 00:00:00 GMT") and format it as index date
 		const dateStr = lines.shift();
-		const dateMoment = moment(dateStr, "DD MMMM YYYY");
+		const dateMoment = parseDate(dateStr || createDate(), "DD MMMM YYYY");
 		if (!dateMoment.isValid()) {
 			throw Error(`Invalid date: "${dateStr}"`);
 		}
diff --git a/src/renderer/store/diary/actionCreators.ts b/src/renderer/store/diary/actionCreators.ts
index 05c23230..0d46f057 100644
--- a/src/renderer/store/diary/actionCreators.ts
+++ b/src/renderer/store/diary/actionCreators.ts
@@ -1,6 +1,7 @@
-import moment from "moment";
+import moment, { Moment } from "moment";
 
 import { MAX_DATE, MIN_DATE } from "../../constants";
+import { createDate, parseDate } from "../../utils/dateFormat";
 import { searchIndex } from "../../utils/searchIndex";
 import { ThunkActionT } from "../store";
 import {
@@ -14,7 +15,7 @@ import {
 
 // Action creators
 
-export function setDateSelected(dateSelected: Date): SetDateSelectedAction {
+export function setDateSelected(dateSelected: Moment): SetDateSelectedAction {
 	let dateValidated = dateSelected;
 	if (dateSelected < MIN_DATE) {
 		dateValidated = MIN_DATE;
@@ -59,20 +60,20 @@ export const setDaySelectedNext = (): ThunkActionT => (dispatch, getState): void
 	const { app, diary } = getState();
 	const { allowFutureEntries } = app;
 	const { dateSelected } = diary;
-	const nextDay = moment(dateSelected).add(1, "days");
-	if (allowFutureEntries || nextDay.isSameOrBefore(moment(), "day")) {
-		dispatch(setDateSelected(nextDay.toDate()));
+	const nextDay = parseDate(dateSelected).add(1, "days");
+	if (allowFutureEntries || nextDay.isSameOrBefore(createDate(), "day")) {
+		dispatch(setDateSelected(nextDay));
 	}
 };
 
 export const setDaySelectedPrevious = (): ThunkActionT => (dispatch, getState): void => {
 	const { dateSelected } = getState().diary;
-	const previousDay = moment(dateSelected).subtract(1, "days");
-	dispatch(setDateSelected(previousDay.toDate()));
+	const previousDay = parseDate(dateSelected).subtract(1, "days");
+	dispatch(setDateSelected(previousDay));
 };
 
 export const setDaySelectedToday = (): ThunkActionT => (dispatch): void => {
-	const today = new Date();
+	const today = createDate();
 	dispatch(setDateSelected(today));
 };
 
@@ -80,18 +81,21 @@ export const setMonthSelectedNext = (): ThunkActionT => (dispatch, getState): vo
 	const { app, diary } = getState();
 	const { allowFutureEntries } = app;
 	const { monthSelected } = diary;
-	const nextMonth = moment(monthSelected)
+	const nextMonth = moment
+		.utc(monthSelected)
 		.add(1, "months")
 		.startOf("month");
-	if (allowFutureEntries || nextMonth.isSameOrBefore(moment(), "month")) {
-		dispatch(setDateSelected(nextMonth.toDate()));
+	const today = createDate();
+	if (allowFutureEntries || nextMonth.isSameOrBefore(today, "month")) {
+		dispatch(setDateSelected(createDate()));
 	}
 };
 
 export const setMonthSelectedPrevious = (): ThunkActionT => (dispatch, getState): void => {
 	const { monthSelected } = getState().diary;
-	const previousMonth = moment(monthSelected)
+	const previousMonth = moment
+		.utc(monthSelected)
 		.subtract(1, "months")
 		.startOf("month");
-	dispatch(setDateSelected(previousMonth.toDate()));
+	dispatch(setDateSelected(previousMonth));
 };
diff --git a/src/renderer/store/diary/reducer.ts b/src/renderer/store/diary/reducer.ts
index b3be3ba0..5133dde1 100644
--- a/src/renderer/store/diary/reducer.ts
+++ b/src/renderer/store/diary/reducer.ts
@@ -1,3 +1,4 @@
+import { createDate } from "../../utils/dateFormat";
 import {
 	DiaryAction,
 	DiaryState,
@@ -6,7 +7,7 @@ import {
 	SET_SEARCH_RESULTS,
 } from "./types";
 
-const today = new Date();
+const today = createDate();
 
 const initialState: DiaryState = {
 	dateSelected: today,
diff --git a/src/renderer/store/diary/types.ts b/src/renderer/store/diary/types.ts
index 55424cf3..5954b022 100644
--- a/src/renderer/store/diary/types.ts
+++ b/src/renderer/store/diary/types.ts
@@ -1,10 +1,11 @@
+import { Moment } from "moment";
 import { Action } from "redux";
 
 // State
 
 export interface DiaryState {
-	dateSelected: Date;
-	monthSelected: Date;
+	dateSelected: Moment;
+	monthSelected: Moment;
 	searchKey: string;
 	searchResults: string[];
 }
@@ -20,7 +21,7 @@ export const SET_SEARCH_RESULTS = "SET_SEARCH_RESULTS";
 export interface SetDateSelectedAction extends Action {
 	type: typeof SET_DATE_SELECTED;
 	payload: {
-		dateSelected: Date;
+		dateSelected: Moment;
 	};
 }
 
diff --git a/src/renderer/store/file/actionCreators.ts b/src/renderer/store/file/actionCreators.ts
index 0ec0bded..bb43eaae 100644
--- a/src/renderer/store/file/actionCreators.ts
+++ b/src/renderer/store/file/actionCreators.ts
@@ -12,7 +12,8 @@ import {
 	writeEncryptedFile,
 } from "../../files/fileAccess";
 import mergeEntries from "../../files/import/mergeEntries";
-import { Entries, MiniDiaryJson, IndexDate } from "../../types";
+import { Entries, IndexDate, MiniDiaryJson } from "../../types";
+import { createDate } from "../../utils/dateFormat";
 import { translations } from "../../utils/i18n";
 import { addIndexDoc, createIndex, removeIndexDoc, updateIndexDoc } from "../../utils/searchIndex";
 import { ThunkActionT } from "../store";
@@ -256,7 +257,7 @@ export const updateEntry = (entryDate: IndexDate, title: string, text: string):
 	} else if (!(entryDate in entries)) {
 		// Entry doesn't exist yet
 		const entryAdded = {
-			dateUpdated: new Date().toString(),
+			dateUpdated: createDate().toString(),
 			title,
 			text,
 		};
@@ -269,7 +270,7 @@ export const updateEntry = (entryDate: IndexDate, title: string, text: string):
 		// Entry has been updated
 		const entryOld = entries[entryDate];
 		const entryUpdated = {
-			dateUpdated: new Date().toString(),
+			dateUpdated: createDate().toString(),
 			title,
 			text,
 		};
diff --git a/src/renderer/utils/dateFormat.ts b/src/renderer/utils/dateFormat.ts
index b14d24e4..a99e87c8 100644
--- a/src/renderer/utils/dateFormat.ts
+++ b/src/renderer/utils/dateFormat.ts
@@ -1,54 +1,76 @@
-import moment from "moment";
+import moment, { Moment, MomentFormatSpecification } from "moment";
 
 import { IndexDate } from "../types";
 
-const INDEX_DATE_FORMAT = "YYYY-MM-DD";
+const DAY_ONE_DATE_FORMAT = "DD MMMM YYYY [at 00:00:00 GMT]"; // E.g. "01 January 2019 at 00:00:00 GMT"
+const DATE_STRING_FORMAT = "LL"; // E.g. "January 1, 2019"
+const FILE_NAME_DATE_FORMAT = "YYYY-MM-DD-HH[h]mm"; // E.g. "2019-01-01-12h30"
+const INDEX_DATE_FORMAT = "YYYY-MM-DD"; // E.g. "2019-01-01"
+const LOCALE_WEEKDAY_FORMAT = "dddd, LL"; // E.g. "Tuesday, January 1, 2019" for "en-us" locale
+const MONTH_YEAR_FORMAT = "MMMM YYYY"; // E.g. "January 2019"
 
 /**
- * Create and return moment object from diary index string
+ * Creates a Moment object instance for the current date and time
  */
-export function momentIndex(dateStr: string): moment.Moment {
-	return moment(dateStr, INDEX_DATE_FORMAT);
+export function createDate(): Moment {
+	return moment.utc();
+}
+
+/**
+ * Creates a Moment object instance for the provided date
+ */
+export function parseDate(
+	date: Date | Moment | string,
+	format?: MomentFormatSpecification,
+): Moment {
+	return moment.utc(date, format);
+}
+
+/**
+ * Create and return Moment object from diary index string
+ */
+export function fromIndexDate(dateString: string): Moment {
+	return parseDate(dateString, INDEX_DATE_FORMAT);
 }
 
 /**
  * Format date as locale-dependent string
  */
-export function toDateString(date: Date | moment.Moment): string {
-	return moment(date).format("LL");
+export function toDateString(date: Moment | string): string {
+	return parseDate(date).format(DATE_STRING_FORMAT);
 }
 
 /**
  * Format date as a string compatible with the import tool of Day One
  */
-export function toDayOneDate(date: Date | moment.Moment): string {
-	return moment(date).format("DD MMMM YYYY [at 00:00:00 GMT]");
+export function toDayOneDate(date: Moment | string): string {
+	return parseDate(date).format(DAY_ONE_DATE_FORMAT);
 }
 
 /**
  * Format date as string for inclusion in file name
  */
-export function toFilenameDate(date: Date | moment.Moment): string {
-	return moment(date).format("YYYY-MM-DD-HH[h]mm");
+export function toFileNameDate(date: Moment | string): string {
+	return parseDate(date).format(FILE_NAME_DATE_FORMAT);
 }
 
 /**
  * Format date as diary index string
  */
-export function toIndexDate(date: Date | moment.Moment): IndexDate {
-	return moment(date).format(INDEX_DATE_FORMAT);
+export function toIndexDate(date: Moment | string): IndexDate {
+	return parseDate(date).format(INDEX_DATE_FORMAT);
 }
 
 /**
  * Format date as locale-dependent string with weekday
  */
-export function toLocaleWeekday(date: Date | moment.Moment): string {
-	return moment(date).format("dddd, LL");
+export function toLocaleWeekday(date: Moment | string): string {
+	return parseDate(date).format(LOCALE_WEEKDAY_FORMAT);
 }
 
 /**
  * Format date as month and year
  */
-export function toMonthYear(date: Date | moment.Moment): string {
-	return moment(date).format("MMMM YYYY");
+export function toMonthYear(date: Moment | string): string {
+	return parseDate(date).format(MONTH_YEAR_FORMAT);
 }
diff --git a/test/import-export/files/jsonMiniDiary.json b/test/import-export/files/jsonMiniDiary.json
index 048d433b..9db750cf 100644
--- a/test/import-export/files/jsonMiniDiary.json
+++ b/test/import-export/files/jsonMiniDiary.json
@@ -2,16 +2,16 @@
 	"metadata": {
 		"application": "Mini Diary",
 		"version": "v0.0.0",
-		"dateUpdated": "Tue Jan 01 2019 00:00:00 GMT+0000 (Greenwich Mean Time)"
+		"dateUpdated": "Tue Jan 01 2019 00:00:00 GMT+0000"
 	},
 	"entries": {
 		"2019-01-01": {
-			"dateUpdated": "Tue Jan 01 2019 00:00:00 GMT+0000 (Greenwich Mean Time)",
+			"dateUpdated": "Tue Jan 01 2019 00:00:00 GMT+0000",
 			"title": "Diary Entry 1",
 			"text": "This text is **bold** and _italic_."
 		},
 		"2019-01-02": {
-			"dateUpdated": "Tue Jan 01 2019 00:00:00 GMT+0000 (Greenwich Mean Time)",
+			"dateUpdated": "Tue Jan 01 2019 00:00:00 GMT+0000",
 			"title": "Diary Entry 2",
 			"text": "Here's a bulleted list:\n\n- One\n- Two\n- Three\n\nAnd here's a numbered list:\n\n1. One\n2. Two\n3. Three"
 		}
diff --git a/test/import-export/referenceData.ts b/test/import-export/referenceData.ts
index 06794a57..ac93e06c 100644
--- a/test/import-export/referenceData.ts
+++ b/test/import-export/referenceData.ts
@@ -3,12 +3,12 @@
  */
 export const referenceDataMd = {
 	"2019-01-01": {
-		dateUpdated: "Tue Jan 01 2019 00:00:00 GMT+0000 (Greenwich Mean Time)",
+		dateUpdated: "Tue Jan 01 2019 00:00:00 GMT+0000",
 		title: "Diary Entry 1",
 		text: "This text is **bold** and _italic_.",
 	},
 	"2019-01-02": {
-		dateUpdated: "Tue Jan 01 2019 00:00:00 GMT+0000 (Greenwich Mean Time)",
+		dateUpdated: "Tue Jan 01 2019 00:00:00 GMT+0000",
 		title: "Diary Entry 2",
 		text:
 			"Here's a bulleted list:\n\n- One\n- Two\n- Three\n\nAnd here's a numbered list:\n\n1. One\n2. Two\n3. Three",
@@ -20,12 +20,12 @@ export const referenceDataMd = {
  */
 export const referenceDataTxt = {
 	"2019-01-01": {
-		dateUpdated: "Tue Jan 01 2019 00:00:00 GMT+0000 (Greenwich Mean Time)",
+		dateUpdated: "Tue Jan 01 2019 00:00:00 GMT+0000",
 		title: "Diary Entry 1",
 		text: "This text is bold and italic.",
 	},
 	"2019-01-02": {
-		dateUpdated: "Tue Jan 01 2019 00:00:00 GMT+0000 (Greenwich Mean Time)",
+		dateUpdated: "Tue Jan 01 2019 00:00:00 GMT+0000",
 		title: "Diary Entry 2",
 		text:
 			"Here's a bulleted list:\n\n- One\n- Two\n- Three\n\nAnd here's a numbered list:\n\n1. One\n2. Two\n3. Three",
diff --git a/test/setup/setup.ts b/test/setup/setup.ts
index a83e8e45..b31c8387 100644
--- a/test/setup/setup.ts
+++ b/test/setup/setup.ts
@@ -1,5 +1,5 @@
 import MockDate from "mockdate";
 
-// Set date for tests to make `new Date()` return the same date as the one used in the sample
-// import/export files. The timezone is set using an environment variable in `package.json`
+// Set date for tests to make `moment()` return the same date as the one used in the sample import/
+// export files
 MockDate.set("Tue Jan 01 2019 00:00:00 GMT+0000");
diff --git a/yarn.lock b/yarn.lock
index d7d1feab..b57002ef 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -3411,13 +3411,6 @@ create-hmac@^1.1.0, create-hmac@^1.1.2, create-hmac@^1.1.4:
     safe-buffer "^5.0.1"
     sha.js "^2.4.8"
 
-cross-env@^7.0.2:
-  version "7.0.2"
-  resolved "https://registry.yarnpkg.com/cross-env/-/cross-env-7.0.2.tgz#bd5ed31339a93a3418ac4f3ca9ca3403082ae5f9"
-  integrity sha512-KZP/bMEOJEDCkDQAyRhu3RL2ZO/SUVrxQVI0G3YEQ+OLbRA3c6zgixe8Mq8a/z7+HKlNEjo8oiLUs8iRijY2Rw==
-  dependencies:
-    cross-spawn "^7.0.1"
-
 cross-spawn@6.0.5, cross-spawn@^6.0.0, cross-spawn@^6.0.5:
   version "6.0.5"
   resolved "https://registry.yarnpkg.com/cross-spawn/-/cross-spawn-6.0.5.tgz#4a5ec7c64dfae22c3a14124dbacdee846d80cbc4"
@@ -3438,7 +3431,7 @@ cross-spawn@^5.0.1:
     shebang-command "^1.2.0"
     which "^1.2.9"
 
-cross-spawn@^7.0.0, cross-spawn@^7.0.1:
+cross-spawn@^7.0.0:
   version "7.0.1"
   resolved "https://registry.yarnpkg.com/cross-spawn/-/cross-spawn-7.0.1.tgz#0ab56286e0f7c24e153d04cc2aa027e43a9a5d14"
   integrity sha512-u7v4o84SwFpD32Z8IIcPZ6z1/ie24O6RU3RbtL5Y316l3KuHVPx9ItBgWQ6VlfAFnRnTtMUrsQ9MUUTuEZjogg==