Add Time#sec_fraction

Mirrors the DateTime#sec_fraction method by returning the fraction
of the second as a Rational.

2 files changed, 11 insertions, 0 deletions

diff --git a/activesupport/CHANGELOG.md b/activesupport/CHANGELOG.md
index 23ca8246e2..1056b6696f 100644
--- a/activesupport/CHANGELOG.md
+++ b/activesupport/CHANGELOG.md
@@ -1,3 +1,7 @@
+*   Add `Time#sec_fraction` to return the fraction of a second as a `Rational`.
+
+    *Andrew White*
+
 *   Add `ActiveSupport.to_time_preserves_timezone` config option to control
     how `to_time` handles timezones. In Ruby 2.4+ the behavior will change
     from converting to the local system timezone to preserving the timezone
diff --git a/activesupport/lib/active_support/core_ext/time/calculations.rb b/activesupport/lib/active_support/core_ext/time/calculations.rb
index 768c9a1b2c..9c019e10b5 100644
--- a/activesupport/lib/active_support/core_ext/time/calculations.rb
+++ b/activesupport/lib/active_support/core_ext/time/calculations.rb
@@ -73,6 +73,13 @@ class Time
     end_of_day.to_i - to_i
   end
 
+  # Returns the fraction of a second as a +Rational+
+  #
+  #    Time.new(2012, 8, 29, 0, 0, 0.5).sec_fraction # => (1/2)
+  def sec_fraction
+    Rational(nsec, 1000000000)
+  end
+
   # Returns a new Time where one or more of the elements have been changed according
   # to the +options+ parameter. The time options (<tt>:hour</tt>, <tt>:min</tt>,
   # <tt>:sec</tt>, <tt>:usec</tt>, <tt>:nsec</tt>) reset cascadingly, so if only