Last active
March 22, 2016 13:23
-
-
Save ViktorovEugene/9584b96a97831c3c460f to your computer and use it in GitHub Desktop.
JS - get the day's number since the 0001-01-01 and conversely - get the date object by the day's number.
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| <!DOCTYPE html> | |
| <html lang="en"> | |
| <head> | |
| <meta charset="UTF-8"> | |
| <title>Date</title> | |
| </head> | |
| <body> | |
| <script> | |
| console.log('\nFrom date to ordinal:\n'); | |
| console.log(toordinal(new Date('1970-01-01'))); | |
| console.log(toordinal(new Date('0001-01-01'))); | |
| console.log(toordinal(new Date('0001-01-02'))); | |
| console.log(toordinal(new Date())); | |
| console.log('\nTo date from ordinal:\n'); | |
| console.log(fromordinal(1)); | |
| console.log(fromordinal(719163)); | |
| console.log(fromordinal(736045)); | |
| function convertMilliSecondsToHours(value) { | |
| return Math.floor(value / ( 24 * 60 * 60 * 1000 )); | |
| } | |
| function toMilliSeconds(value) { | |
| return value * ( 24 * 60 * 60 * 1000 ) | |
| } | |
| function toordinal(date) { | |
| /* This is the js implementation of the python's | |
| ``datetime.date.toordinal()`` method. | |
| It return the days number since the 0001-01-01 | |
| (it counts as the first day). | |
| For example for the ``new Date('0001-01-01')`` it will be ``1``; | |
| */ | |
| var zeroDate = new Date('0000-12-31'), | |
| zeroDays = Math.abs( | |
| convertMilliSecondsToHours(zeroDate.getTime()) | |
| ); | |
| return zeroDays + | |
| convertMilliSecondsToHours(date.getTime()); | |
| } | |
| function fromordinal(daysNumber) { | |
| /* This is the JS implementation of the python's | |
| * ``datetime.date.fromordinal()`` method. | |
| * It returns the date object gotten from the day's number | |
| * if we take the first day as the 1 January of the 0001 year. | |
| */ | |
| var zeroMilliSecond = new Date('0000-12-31'); | |
| zeroMilliSecond.setHours(0); | |
| zeroMilliSecond = zeroMilliSecond.getTime(); | |
| return new Date(toMilliSeconds(daysNumber) + zeroMilliSecond); | |
| } | |
| </script> | |
| </body> | |
| </html> |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment