RoundUpToQuarter.Rmd

# *Round up* a date object to the latest quarter

It might be useful to *round up* a date to the quarter it is in.
Rounding to the current month or year is trivial, but it's tricky when we want
to round to the quarter.

The output is a date class object.

First, create a fake dataset.

```{r}
x <- c("2014-01-14", "2012-03-30", "2010-04-02", "2011-06-01", "2011-08-23", "2011-09-01", "2012-12-30", "2011-12-31")
x <- as.Date(x)
```

Next, create some intermediate, helper variables.

```{r}
yy <- year(x)
mm <- ceiling(month(x) / 3) * 3
dd <- ifelse(mm == 3, 31, ifelse(mm == 6, 30, ifelse(mm == 9, 30, ifelse(mm == 12, 31, NA))))
```

Then, `paste` the helper variables to a date class object.

```{r}
qtr <- as.Date(paste(yy, mm, dd, sep="-"))
```

Combine the vectors to a data frame.

```{r}
D <- data.frame(dateOriginal = x, dateQuarter = qtr)
```

Show the resulting date class object.

```{r}
str(D)
D
```