dojo.date.add() calculations don't respect time zones properly

[guest]

I encounter a strange problem. Having _Calendar widget for December 2007 printed out, once I click on 1-DEC-2007, both 1-DEC-2007 and 1-JAN-2008 become selected (dijitCalendarSelectedDate).
I've done some debugging (you might find this helpful):
I've inspected what happens when printing dates in _populateGrid of _Calendar, especially for dates in next month (JAN-2008):
After _Calendar.js:82, var date = new Date(month); the date is:

• date.toString() = "Sat Dec 01 2007 00:00:00 GMT+0100 (Central European Standard Time)"
• date.toUTCString() = "Fri, 30 Nov 2007 23:00:00 GMT"
• date.getTime() = 1196463600000

Then let's assume adj = 1 in the if-branch (_Calendar.js:85-96). And then happens: date = dojo.date.add(date, "month", adj); (_Calendar.js:99). And after that the value is:

• date.toString() = "Mon Dec 31 2007 00:00:00 GMT+0100 (Central European Standard Time)"
• date.toUTCString() = "Sun, 30 Dec 2007 23:00:00 GMT"
• date.getTime() = 1199055600000

Which seems wrong to me. In consequence when printing first 5 days for JAN-2008 it iterates between 1-DEC-2007 and 5-DEC-2007, because date.setDate(1) returns 1-DEC-2007, not 1-JAN-2008. (NB: for previous month dates it iterates over OCT-2007, not NOV-2007)
Some additional info:

• dojo.date.getTimezoneName(new Date()) = "Central European Standard Time"
• dojo version is 1.0.2

If you need some more information, please let me know.

[guest]

Even a simpler example would be:

dojo.date.add(new Date(2007,11,1), "month", 1) = Mon Dec 31 2007 00:00:00 GMT+0100 (Central European Standard Time)

which it's not a problem for me, but _Calendar expects something else. I can only guess that's more a dojo/date.js issue, rather than dijit._Calendar.

[guest]

A workaround would be to follow this:

dojo.date.add(new Date(2007,11,1,12,0,0), "month",1) = Tue Jan 01 2008 12:00:00 GMT+0100 (Central European Standard Time)

[Adam Peller]

Sounds related to the UTC date patch #5315 that went into 1.0.2. Bryan, can you take a look?

[Bryan Forbes]

I need to know two things before I can really diagnose (and replicate) this bug:

• What OS and browser you are using.
• What timezone you are using in your OS configuration (I couldn't find a timezone that output Central European Standard Time in Firefox).

Using Firefox in Ubuntu 7.10 and the following timezones, I get these results:

America/Chicago (CST):
>>> new Date(2007,11,1)
Sat Dec 01 2007 00:00:00 GMT-0600 (CST)
>>> dojo.date.add(new Date(2007,11,1), "month", 1)
Tue Jan 01 2008 00:00:00 GMT-0600 (CST)

Europe/Berlin (CET):
>>> new Date(2007,11,1)
Sat Dec 01 2007 00:00:00 GMT+0100 (CET)
>>> dojo.date.add(new Date(2007,11,1), "month", 1)
Tue Jan 01 2008 00:00:00 GMT+0100 (CET)

[guest]

Hi,

Originally I had observed the problem on Windows XP EN, 32-bit, Firefox 2.0.x, locale: Poland (I will try to give you the exact details tomorrow). Now I am sitting in front of Firefox on Ubuntu 7.10 as well, 2.6.22-14-generic, and I can only confirm that here it's OK.

Regards, Grzegorz Oledzki

[guest]

Hm... At the moment I can't reproduce the problem either. Hmmm. I'll come back to you as soon as I am able to reproduce it myself. I am sure the problem had really taken place, because I've been pasting the outputs directly from the browser.

FYI: I use Windows XP Pro, Version 2002, Service Pack 2, and "Date and time" settings (in Systray | Clock | Adjust Date and Time) report "Current time zone: Central European Standard Time". Time zone chosen is "(GMT+01:00) Sarajevo, Skopje, Warsaw, Zagreb". Firefox is "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.11) Gecko/20071127 Firefox/2.0.0.11".

[guest]

For last couple of weeks the problem has not re-appeared in our application, although we're still using the same Dojo (1.0.2), and the same components. I guess I must've been doing something wrong. I think you can close this ticket. Thanks anyway...

Regards, Grzegorz Olędzki

[Adam Peller]

ugh. this timezone stuff makes me nervous. we did make a fix in 1.1 to use the date constructor once and not use the accessors. this seems to help with some odd cases, but mostly where historical cases are a problem (like initially setting a date to 1972 then changing the year, and problems with daylight savings)

do let us know if anything comes up

[guest]

OK

Grzegorz

[(none)]

Milestone 1.0.3 deleted