1 files changed, 32 insertions, 14 deletions
diff --git a/activesupport/lib/active_support/core_ext/date_time/calculations.rb b/activesupport/lib/active_support/core_ext/date_time/calculations.rb
index 6f730e4b6f..fd78044b5d 100644
--- a/activesupport/lib/active_support/core_ext/date_time/calculations.rb
+++ b/activesupport/lib/active_support/core_ext/date_time/calculations.rb
@@ -4,8 +4,8 @@ class DateTime
   class << self
     # *DEPRECATED*: Use +DateTime.civil_from_format+ directly.
     def local_offset
-      ActiveSupport::Deprecation.warn 'DateTime.local_offset is deprecated. ' \
-        'Use DateTime.civil_from_format directly.', caller
+      ActiveSupport::Deprecation.warn 'DateTime.local_offset is deprecated. Use DateTime.civil_from_format directly.', caller
+
       ::Time.local(2012).utc_offset.to_r / 86400
     end
 
@@ -35,14 +35,14 @@ class DateTime
   # minute is passed, then sec is set to 0.
   def change(options)
     ::DateTime.civil(
-      options[:year]  || year,
-      options[:month] || month,
-      options[:day]   || day,
-      options[:hour]  || hour,
-      options[:min]   || (options[:hour] ? 0 : min),
-      options[:sec]   || ((options[:hour] || options[:min]) ? 0 : sec),
-      options[:offset]  || offset,
-      options[:start]  || start
+      options.fetch(:year, year),
+      options.fetch(:month, month),
+      options.fetch(:day, day),
+      options.fetch(:hour, hour),
+      options.fetch(:min, options[:hour] ? 0 : min),
+      options.fetch(:sec, (options[:hour] || options[:min]) ? 0 : sec),
+      options.fetch(:offset, offset),
+      options.fetch(:start, start)
     )
   end
 
@@ -53,8 +53,16 @@ class DateTime
   def advance(options)
     d = to_date.advance(options)
     datetime_advanced_by_date = change(:year => d.year, :month => d.month, :day => d.day)
-    seconds_to_advance = (options[:seconds] || 0) + (options[:minutes] || 0) * 60 + (options[:hours] || 0) * 3600
-    seconds_to_advance == 0 ? datetime_advanced_by_date : datetime_advanced_by_date.since(seconds_to_advance)
+    seconds_to_advance = \
+      options.fetch(:seconds, 0) +
+      options.fetch(:minutes, 0) * 60 +
+      options.fetch(:hours, 0) * 3600
+
+    if seconds_to_advance.zero?
+      datetime_advanced_by_date
+    else
+      datetime_advanced_by_date.since seconds_to_advance
+    end
   end
 
   # Returns a new DateTime representing the time a number of seconds ago
@@ -83,10 +91,19 @@ class DateTime
     change(:hour => 23, :min => 59, :sec => 59)
   end
 
+  # Returns a new DateTime representing the start of the hour (hh:00:00)
+  def beginning_of_hour
+    change(:min => 0)
+  end
+  alias :at_beginning_of_hour :beginning_of_hour
+
+  # Returns a new DateTime representing the end of the hour (hh:59:59)
+  def end_of_hour
+    change(:min => 59, :sec => 59)
+  end
+
   # Adjusts DateTime to UTC by adding its offset value; offset is set to 0
   #
-  # Example:
-  #
   #   DateTime.civil(2005, 2, 21, 10, 11, 12, Rational(-6, 24))       # => Mon, 21 Feb 2005 10:11:12 -0600
   #   DateTime.civil(2005, 2, 21, 10, 11, 12, Rational(-6, 24)).utc   # => Mon, 21 Feb 2005 16:11:12 +0000
   def utc
@@ -108,4 +125,5 @@ class DateTime
   def <=>(other)
     super other.to_datetime
   end
+
 end