Question

Consider this gist: https://gist.github.com/752934

When converting from String to Time everything goes well. It returns as UTC. However, when you convert from time to time it returns as WEST instead of UTC (or returning self: http://api.rubyonrails.org/classes/Time.html#method-i-to_time)

Any idea on why is the time zone being changed from UTC to WEST?

Thanks in advance,
DBA

Answer 1

I am guessing it suffers from the same problem as DateTime.to_time. This was submitted as a bug in Ruby, but rejected. More info here:

http://redmine.ruby-lang.org/issues/show/3737

UPDATE:
https://github.com/rails/rails/blob/master/activesupport/lib/active_support/core_ext/time/conversions.rb

Looks like API doc is out of date. There is a condition on the method to check if to_time is already defined. So looks like its not even hitting this ext method:

  # A method to keep Time, Date and DateTime instances interchangeable on conversions.
  # In this case, it simply returns +self+.
  def to_time
    self
  end unless method_defined?(:to_time)

Here is the commit: https://github.com/rails/rails/blob/4817bf94d135c44ddfae1a30acb15de989e3c86c/activesupport/lib/active_support/core_ext/time/conversions.rb

I tested out monkey patching and it works like you would expect:

ruby-1.9.2-p0 > class Time
ruby-1.9.2-p0 ?>  def to_time
ruby-1.9.2-p0 ?>    self
ruby-1.9.2-p0 ?>  end
ruby-1.9.2-p0 ?>end
 => nil 
ruby-1.9.2-p0 > Time.zone = Time.zone_default = "UTC"
 => "UTC" 
ruby-1.9.2-p0 > t = "2008-04-01".to_time
 => 2008-04-01 00:00:00 UTC 
ruby-1.9.2-p0 >  p t.zone, t.to_time.zone
"UTC"
"UTC"
 => ["UTC", "UTC"] 

I would consider this a bug