Fix handling of offsets with Time#to_s(:iso8601)

Use a lambda to ensure that the generated string respects the offset of
the time value. Also add DateTime#to_s(:iso8601) and Date#to_s(:iso8601)
for completeness.

1 files changed, 2 insertions, 1 deletions

diff --git a/activesupport/lib/active_support/core_ext/time/conversions.rb b/activesupport/lib/active_support/core_ext/time/conversions.rb
index a87455dedb..9fd26156c7 100644
--- a/activesupport/lib/active_support/core_ext/time/conversions.rb
+++ b/activesupport/lib/active_support/core_ext/time/conversions.rb
@@ -17,7 +17,7 @@ class Time
       offset_format = time.formatted_offset(false)
       time.strftime("%a, %d %b %Y %H:%M:%S #{offset_format}")
     },
-    :iso8601      => "%Y-%m-%dT%H:%M:%SZ"
+    :iso8601      => lambda { |time| time.iso8601 }
   }
 
   # Converts to a formatted string. See DATE_FORMATS for builtin formats.
@@ -35,6 +35,7 @@ class Time
   #   time.to_formatted_s(:long)         # => "January 18, 2007 06:10"
   #   time.to_formatted_s(:long_ordinal) # => "January 18th, 2007 06:10"
   #   time.to_formatted_s(:rfc822)       # => "Thu, 18 Jan 2007 06:10:17 -0600"
+  #   time.to_formatted_s(:iso8601)      # => "2007-01-18T06:10:17-06:00"
   #
   # == Adding your own time formats to +to_formatted_s+
   # You can add your own formats to the Time::DATE_FORMATS hash.