title | tags | firstSeen | lastUpdated |
---|---|---|---|
dayOfYear |
date,beginner |
2018-09-29 13:22:20 +0300 |
2020-10-19 18:51:03 +0300 |
Gets the day of the year (number in the range 1-366) from a Date
object.
- Use
new Date()
andDate.prototype.getFullYear()
to get the first day of the year as aDate
object. - Subtract the first day of the year from
date
and divide with the milliseconds in each day to get the result. - Use
Math.floor()
to appropriately round the resulting day count to an integer.
const dayOfYear = date =>
Math.floor((date - new Date(date.getFullYear(), 0, 0)) / 1000 / 60 / 60 / 24);
dayOfYear(new Date()); // 272