# Yet Another Time Zone Question **URL:** \ **Category:** Rails\ **Created:** [May 12, 2009, 9:56am UTC](https://www.ruby-forum.com/t/yet-another-time-zone-question/167757 "2009-05-12T09:56:32Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![randall](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/b38774/32.png) [@randall](https://www.ruby-forum.com/u/randall)\ **Post date:** [May 12, 2009, 9:56am UTC](https://www.ruby-forum.com/t/yet-another-time-zone-question/167757/1 "2009-05-12T09:56:32Z")
Seems like there should be an easy solution to this problem, yet I can’t seem to find one. Here is the issue: How do you assign a time zone to a Time object that results from a parsed date/time string? Example: - I receive a date time string from a date picker widget that does not include time zone info (i.e. “Mon May 11 18:24:37 2009”). - Time zone for this date is known and may be different than what’s local to the user - date/time is stored in the DB as unix time (i.e. 1242075962) - time zone is stored in the DB in tz format i(i.e. ‘America/ New\_York’) - I would like to be able to take a given date with its known time zone and calculate the equivalent unix time value. > > now = Time.now > > =\> Mon May 11 18:24:37 -0400 2009 > > > now.to\_i > > =\> 1242080677 > > parsed = DateTime.parse(“Mon May 11 18:24:37 2009”) > > =\> Mon, 11 May 2009 18:24:37 +0000 > > > parsed.to\_time > > =\> Mon May 11 18:24:37 UTC 2009 > > > parsed.to\_time.to\_i > > =\> 1242066277 > > > Time.at 1242066277 > > =\> Mon May 11 14:24:37 -0400 2009 It seems there should be a way to append the time zone to the string before it is parsed or to associate the parsed time with a time zone (without converting the time to the zone), however I can’t seem to find an answer. Any help would be greatly appreciated ---
**Author:** ![randall](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/b38774/32.png) [@randall](https://www.ruby-forum.com/u/randall)\ **Post date:** [May 13, 2009, 12:32am UTC](https://www.ruby-forum.com/t/yet-another-time-zone-question/167757/2 "2009-05-13T00:32:07Z")
Hi, The time zone is encoded in the string at the end e.g Mon, 11 May 2009 18:24:37 +1200 Is in a time zone that’s +12 (12 hours ahead of utc) DateTime.parse or Time.parse will read this correctly. So what you’re doing is using a js date picker that gives you a string like “Mon May 11 18:24:37 2009” You just need to append the time zone difference to “Mon May 11 18:24:37 2009 +1200” etc before parsing. I handle storing dates in the db a little differently than you, but if you know what you’re doing don’t worry about changing that part. I usually store dates in the db in utc format (I think you can configure this in environment.rb from memory), and you can easily set the user’s timezone in a filter in application controller Time.zone = user.time\_zone which will handle all of the conversions for you. Cheers, Jeremy ---
**Author:** ![randall](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/b38774/32.png) [@randall](https://www.ruby-forum.com/u/randall)\ **Post date:** [May 13, 2009, 9:34pm UTC](https://www.ruby-forum.com/t/yet-another-time-zone-question/167757/3 "2009-05-13T21:34:38Z")
Thanks Jeremy! ---
**Author:** ![randall](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/b38774/32.png) [@randall](https://www.ruby-forum.com/u/randall)\ **Post date:** [May 18, 2009, 9:12pm UTC](https://www.ruby-forum.com/t/yet-another-time-zone-question/167757/4 "2009-05-18T21:12:20Z")
On Tue, May 12, 2009 at 6:31 PM, Jeremy Olliver [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > > include time zone info (i.e. “Mon May 11 18:24:37 2009”). > > > > - Time zone for this date is known and may be different than what’s > > local to the user > > - date/time is stored in the DB as unix time (i.e. 1242075962) > > - time zone is stored in the DB in tz format i(i.e. ‘America/ > > New\_York’) > > - I would like to be able to take a given date with its known time > > zone and calculate the equivalent unix time value. > > … > > > > It seems there should be a way to append the time zone to the string > > before it is parsed or to associate the parsed time with a time zone > > (without converting the time to the zone), however I can’t seem to > > find an answer. > > > > > > The time zone is encoded in the string at the end e.g > > Mon, 11 May 2009 18:24:37 +1200 > Is in a time zone that’s +12 (12 hours ahead of utc) > DateTime.parse or Time.parse will read this correctly. > > So what you’re doing is using a js date picker that gives you a string > like “Mon May 11 18:24:37 2009” > You just need to append the time zone difference to “Mon May 11 > 18:24:37 2009 +1200” etc before parsing. Careful here, there’s a diference between a time zone like “America/New\_York” and a time zone offset [http://www.w3.org/TR/timezone/](http://www.w3.org/TR/timezone/) > I handle storing dates in the db a little differently than you, but if > you know what you’re doing don’t worry about changing that part. > I usually store dates in the db in utc format (I think you can > configure this in environment.rb from memory), and you can easily set > the user’s timezone in a filter in application controller > Time.zone = user.time\_zone > which will handle all of the conversions for you. Or to convert to an arbitrary timezone Time.at(unix\_time).in\_timezone('America/New\_York") – Rick DeNatale Blog: [http://talklikeaduck.denhaven2.com/](http://talklikeaduck.denhaven2.com/) Twitter: [http://twitter.com/RickDeNatale](http://twitter.com/RickDeNatale) WWR: [http://www.workingwithrails.com/person/9021-rick-denatale](http://www.workingwithrails.com/person/9021-rick-denatale) LinkedIn: [http://www.linkedin.com/in/rickdenatale](http://www.linkedin.com/in/rickdenatale)