Using the Javascript calendar popup to return year/dayofyear (%Y/%j), the day of year is incorrect by one day for any day of the year after March 9. Both March 9 and March 10, 2008 produce DOY 069.

This is because the doy is calculated as (milliseconds(today) - milliseconds(Jan 1))/86400000; after March 9, milliseconds(today) includes an extra hour due to daylight savings time. This throws off the calculation enough to cause a roundoff error.

I modified two files in directory atlassian-jira/includes/js/calendar: calendar.js and calendar-min.js, changing the getDayOfYear function to use UTC in its calculation, rather than local machine time. Here is a diff of calendar.js showing the changes:

1. diff calendar.js calendar.js~
   1833,1834c1833,1834
   < var now = Date.UTC(this.getFullYear(), this.getMonth(), this.getDate(), 0, 0, 0);
   < var then = Date.UTC(this.getFullYear(), 0, 1, 0, 0, 0);

   • • > var now = new Date(this.getFullYear(), this.getMonth(), this.getDate(), 0, 0, 0);
       > var then = new Date(this.getFullYear(), 0, 0, 0, 0, 0);
       1836c1836
       < return Math.floor(time / Date.DAY) + 1;

     • > return Math.floor(time / Date.DAY);

A corresponding change is required in calendar-min.js.

This probably affects every version of Jira that uses the calendar popup. However it only affects the day of year calculation, and should not be a problem for other date formats.