ActiveSupport、Time#in_time_zone

everyday Ruby

まんま

>> require "rubygems"
=> true
>> require "active_support"
=> true
>> Time.zone
=> nil
>> Time.local(2008).in_time_zone
NoMethodError: undefined method `period_for_utc' for nil:NilClass
>> Time.zone = 'Tokyo'
=> "Tokyo"
>> Time.local(2008).in_time_zone
=> Tue, 01 Jan 2008 00:00:00 JST +09:00
>> Time.utc(2008).in_time_zone
=> Tue, 01 Jan 2008 09:00:00 JST +09:00
>> Time.zone = nil
=> nil
>> Time.utc(2008).in_time_zone('Tokyo')
=> Tue, 01 Jan 2008 09:00:00 JST +09:00