Rails ActiveSupport Time Parsing?

It looks like ActiveSupport does provide the parsing methods you are looking for (and I was looking for too), after all! — at least if the string you are trying to parse is a standard, ISO-8601-formatted (:db format) date.

If the date you're trying to parse is already in your local time zone, it's really easy!

 > Time.zone.parse('2009-09-24 08:28:43')=> Thu, 24 Sep 2009 08:28:43 PDT -07:00 > Time.zone.parse('2009-09-24 08:28:43').class=> ActiveSupport::TimeWithZone

and that time-zone-aware time can then easily be converted to UTC

 > Time.zone.parse('2009-09-24 08:28:43').utc=> 2009-09-24 15:28:43 UTC

or to other time zones:

 > ActiveSupport::TimeZone.us_zones.map(&:name)=> ["Hawaii", "Alaska", "Pacific Time (US & Canada)", "Arizona", "Mountain Time (US & Canada)", "Central Time (US & Canada)", "Eastern Time (US & Canada)", "Indiana (East)"] > Time.zone.parse('2009-09-24 08:28:43').utc.in_time_zone('Eastern Time (US & Canada)')=> Thu, 24 Sep 2009 11:28:43 EDT -04:00

If the date string you're trying to parse is in UTC, on the other hand, it doesn't look like there's any method to parse it directly into a TimeWithZone, but I was able to work around that be first using DateTime.strptime...

If the date you're trying to parse is in UTC and you want it to stay as UTC, you can use:

 > DateTime.strptime('2009-09-24 08:28:43', '%Y-%m-%d %H:%M:%S').to_time=> 2009-09-24 08:28:43 UTC

If the date you're trying to parse is in UTC and you want it converted to your default time zone, you can use:

 > DateTime.strptime('2009-09-24 08:28:43', '%Y-%m-%d %H:%M:%S').to_time.in_time_zone=> Thu, 24 Sep 2009 01:28:43 PDT -07:00

It looks like it can even parse other formats, such as the strange format that Time#to_s produces:

irb -> Time.zone.parse('Wed, 23 Sep 2009 02:18:08').to_s(:db)    => "2009-09-23 09:18:08"irb -> Time.zone.parse('Wed, 23 Sep 2009 02:18:08 EDT').to_s(:db)    => "2009-09-23 06:18:08"

I'm quite impressed.

Here are some more examples from [http://api.rubyonrails.org/classes/ActiveSupport/TimeWithZone.html][1]:

  Time.zone = 'Eastern Time (US & Canada)'        # => 'Eastern Time (US & Canada)'  Time.zone.local(2007, 2, 10, 15, 30, 45)        # => Sat, 10 Feb 2007 15:30:45 EST -05:00  Time.zone.parse('2007-02-10 15:30:45')          # => Sat, 10 Feb 2007 15:30:45 EST -05:00  Time.zone.at(1170361845)                        # => Sat, 10 Feb 2007 15:30:45 EST -05:00  Time.zone.now                                   # => Sun, 18 May 2008 13:07:55 EDT -04:00  Time.utc(2007, 2, 10, 20, 30, 45).in_time_zone  # => Sat, 10 Feb 2007 15:30:45 EST -05:00

More documentation links for reference:

• http://api.rubyonrails.org/classes/ActiveSupport/TimeWithZone.html
• http://api.rubyonrails.org/classes/ActiveSupport/TimeZone.html

ActiveSupport::TimeZone.new('UTC').parse('2009-09-23 09:18:08')=> Wed, 23 Sep 2009 09:18:08 UTC +00:00

Rails 5 finally provides strptime!

value = '1999-12-31 14:00:00'format = '%Y-%m-%d %H:%M:%S'Time.zone.strptime(value, format)# => Fri, 31 Dec 1999 14:00:00 HST -10:00ActiveSupport::TimeZone.all.sample.strptime(value, format)# => Fri, 31 Dec 1999 14:00:00 GST +04:00