In Rails, how do I convert and print a time to a different time zone?

Question

I have a variable, start_time:

(rdb:5) start_time.class
ActiveSupport::TimeWithZone

(rdb:5) start_time
Tue, 23 Feb 2010 14:45:00 EST -05:00

(rdb:5) start_time.in_time_zone(ActiveSupport::TimeZone::ZONES_MAP["Pacific Time (US & Canada)"]).zone
"PST"

(rdb:5) start_time.in_time_zone(ActiveSupport::TimeZone::ZONES_MAP["Pacific Time (US & Canada)"]).to_s(:time)
"2:45 PM ET"

I'd like to change 'to_s(:time)' so that it outputs the time in whatever zone is specified in the variable, not the default system time. I.e. The output would be "11:45 AM PT". How do I do this?

Answer 1

I ran into this issue recently and was able to solve it by essentially overriding the .to_s option that I was using. I created an initializer called time_formats.rb and added the following line to it.

Time::DATE_FORMATS[:time_in_zone] = "%H:%M %p"

then changed (:time) to (:time_in_zone) like so...

start_time.in_time_zone(...your timezone here...]).to_s(:time_in_zone)

It should give you the time in the zone you are specifying. My environment is in UTC, so maybe that had something to do with it...

Answer 2

I think you want to create a TimeZone object, and use its at() method:

start_time = Time.now 
start_time.rfc822                          # => "Tue, 23 Feb 2010 10:58:23 -0500"
pst = ActiveSupport::TimeZone["Pacific Time (US & Canada)"]
pst.at(start_time).strftime("%H:%M %p %Z") # => "08:00 AM PST"

Answer 3

Given Beerlington's comments, I ended up adding the following (which is similar to the Proc defined for Time::DATE_FORMATS[:time]

:time_in_zone  => lambda { |time|
    time = time.strftime("%I:%M %p %Z").gsub(/([NAECMP])([DS])T$/, '\1T')
    time = time[1..-1] if time =~ /^0/ # drop leading zeroes
    time
}