beginning_of_week extended in both Time and Date so that to return week start...

beginning_of_week extended in both Time and Date so that to return week start based on start day that is monday by default

activesupport/lib/active_support/core_ext/date/calculations.rb

@@ -174,19 +174,27 @@ def next_month
     months_since(1)
   end unless method_defined?(:next_month)
 
-  # Returns a new Date/DateTime representing the "start" of this week (i.e, Monday; DateTime objects will have time set to 0:00).
-  def beginning_of_week
-    days_to_monday = self.wday!=0 ? self.wday-1 : 6
-    result = self - days_to_monday
+  # Returns number of days to start of this week, week starts on start_day (default is Monday)
+  def days_to_week_start(start_day = :monday)
+    start_day_number = DAYS_INTO_WEEK[start_day]
+    current_day_number = wday != 0 ? wday - 1 : 6
+    days_span = current_day_number - start_day_number
+    days_span >= 0 ? days_span : 7 + days_span
+  end
+
+  # Returns a new Date/DateTime representing the "start" of this week, week starts on start_day (i.e, Monday; DateTime objects will have time set to 0:00).
+  def beginning_of_week(start_day = :monday)
+    days_to_start = days_to_week_start(start_day)
+    result = self - days_to_start
     self.acts_like?(:time) ? result.midnight : result
   end
   alias :monday :beginning_of_week
   alias :at_beginning_of_week :beginning_of_week
 
-  # Returns a new Date/DateTime representing the end of this week (Sunday, DateTime objects will have time set to 23:59:59).
-  def end_of_week
-    days_to_sunday = self.wday!=0 ? 7-self.wday : 0
-    result = self + days_to_sunday.days
+  # Returns a new Date/DateTime representing the end of this week, week starts on start_day (Sunday, DateTime objects will have time set to 23:59:59).
+  def end_of_week(start_day = :monday)
+    days_to_end = 6 - days_to_week_start(start_day)
+    result = self + days_to_end.days
     self.acts_like?(:time) ? result.end_of_day : result
   end
   alias :sunday :end_of_week

activesupport/lib/active_support/core_ext/time/calculations.rb

@@ -161,18 +161,26 @@ def next_month
     months_since(1)
   end
 
-  # Returns a new Time representing the "start" of this week (Monday, 0:00)
-  def beginning_of_week
-    days_to_monday = wday!=0 ? wday-1 : 6
-    (self - days_to_monday.days).midnight
+  # Returns number of days to start of this week, week starts on start_day (default is Monday)
+  def days_to_week_start(start_day = :monday)
+    start_day_number = DAYS_INTO_WEEK[start_day]
+    current_day_number = wday != 0 ? wday - 1 : 6
+    days_span = current_day_number - start_day_number
+    days_span >= 0 ? days_span : 7 + days_span
+  end
+
+  # Returns a new Time representing the "start" of this week, week starts on start_day (deafult is Monday, e.g. Monday, 0:00)
+  def beginning_of_week(start_day = :monday)
+    days_to_start = days_to_week_start(start_day)
+    (self - days_to_start.days).midnight
   end
   alias :monday :beginning_of_week
   alias :at_beginning_of_week :beginning_of_week
 
-  # Returns a new Time representing the end of this week, (end of Sunday)
-  def end_of_week
-    days_to_sunday = wday!=0 ? 7-wday : 0
-    (self + days_to_sunday.days).end_of_day
+  # Returns a new Time representing the end of this week, week starts on start_day (deafult is Monday, end of Sunday)
+  def end_of_week(start_day = :monday)
+    days_to_end =  6 - days_to_week_start(start_day)
+    (self + days_to_end.days).end_of_day
   end
   alias :at_end_of_week :end_of_week
 

activesupport/test/core_ext/date_time_ext_test.rb

@@ -54,6 +54,24 @@ def test_seconds_since_midnight
     assert_equal 86399,DateTime.civil(2005,1,1,23,59,59).seconds_since_midnight
   end
 
+  def test_days_to_week_start
+    assert_equal 0, Time.local(2011,11,01,0,0,0).days_to_week_start(:tuesday)
+    assert_equal 1, Time.local(2011,11,02,0,0,0).days_to_week_start(:tuesday)
+    assert_equal 2, Time.local(2011,11,03,0,0,0).days_to_week_start(:tuesday)
+    assert_equal 3, Time.local(2011,11,04,0,0,0).days_to_week_start(:tuesday)
+    assert_equal 4, Time.local(2011,11,05,0,0,0).days_to_week_start(:tuesday)
+    assert_equal 5, Time.local(2011,11,06,0,0,0).days_to_week_start(:tuesday)
+    assert_equal 6, Time.local(2011,11,07,0,0,0).days_to_week_start(:tuesday)
+
+    assert_equal 3, Time.local(2011,11,03,0,0,0).days_to_week_start(:monday)
+    assert_equal 3, Time.local(2011,11,04,0,0,0).days_to_week_start(:tuesday)
+    assert_equal 3, Time.local(2011,11,05,0,0,0).days_to_week_start(:wednesday)
+    assert_equal 3, Time.local(2011,11,06,0,0,0).days_to_week_start(:thursday)
+    assert_equal 3, Time.local(2011,11,07,0,0,0).days_to_week_start(:friday)
+    assert_equal 3, Time.local(2011,11,8,0,0,0).days_to_week_start(:saturday)
+    assert_equal 3, Time.local(2011,11,9,0,0,0).days_to_week_start(:sunday)
+  end
+
   def test_beginning_of_week
     assert_equal DateTime.civil(2005,1,31), DateTime.civil(2005,2,4,10,10,10).beginning_of_week
     assert_equal DateTime.civil(2005,11,28), DateTime.civil(2005,11,28,0,0,0).beginning_of_week #monday

activesupport/test/core_ext/time_ext_test.rb

@@ -59,8 +59,28 @@ def test_beginning_of_week
     assert_equal Time.local(2005,11,28), Time.local(2005,12,02,0,0,0).beginning_of_week #friday
     assert_equal Time.local(2005,11,28), Time.local(2005,12,03,0,0,0).beginning_of_week #saturday
     assert_equal Time.local(2005,11,28), Time.local(2005,12,04,0,0,0).beginning_of_week #sunday
+
   end
 
+  def test_days_to_week_start
+    assert_equal 0, Time.local(2011,11,01,0,0,0).days_to_week_start(:tuesday)
+    assert_equal 1, Time.local(2011,11,02,0,0,0).days_to_week_start(:tuesday)
+    assert_equal 2, Time.local(2011,11,03,0,0,0).days_to_week_start(:tuesday)
+    assert_equal 3, Time.local(2011,11,04,0,0,0).days_to_week_start(:tuesday)
+    assert_equal 4, Time.local(2011,11,05,0,0,0).days_to_week_start(:tuesday)
+    assert_equal 5, Time.local(2011,11,06,0,0,0).days_to_week_start(:tuesday)
+    assert_equal 6, Time.local(2011,11,07,0,0,0).days_to_week_start(:tuesday)
+
+    assert_equal 3, Time.local(2011,11,03,0,0,0).days_to_week_start(:monday)
+    assert_equal 3, Time.local(2011,11,04,0,0,0).days_to_week_start(:tuesday)
+    assert_equal 3, Time.local(2011,11,05,0,0,0).days_to_week_start(:wednesday)
+    assert_equal 3, Time.local(2011,11,06,0,0,0).days_to_week_start(:thursday)
+    assert_equal 3, Time.local(2011,11,07,0,0,0).days_to_week_start(:friday)
+    assert_equal 3, Time.local(2011,11,8,0,0,0).days_to_week_start(:saturday)
+    assert_equal 3, Time.local(2011,11,9,0,0,0).days_to_week_start(:sunday)
+  end
+
+
   def test_beginning_of_day
     assert_equal Time.local(2005,2,4,0,0,0), Time.local(2005,2,4,10,10,10).beginning_of_day
     with_env_tz 'US/Eastern' do

railties/guides/source/active_support_core_extensions.textile

@@ -3039,12 +3039,14 @@ Active Support defines these methods as well for Ruby 1.8.
 
 h6. +beginning_of_week+, +end_of_week+
 
-The methods +beginning_of_week+ and +end_of_week+ return the dates for the beginning and end of week, assuming weeks start on Monday:
+The methods +beginning_of_week+ and +end_of_week+ receive a symbol with a day name in English (in lowercase, default is :monday) and return the dates for the beginning and end of week, assuming weeks start on day, passed as parameter:
 
 <ruby>
-d = Date.new(2010, 5, 8) # => Sat, 08 May 2010
-d.beginning_of_week      # => Mon, 03 May 2010
-d.end_of_week            # => Sun, 09 May 2010
+d = Date.new(2010, 5, 8)     # => Sat, 08 May 2010
+d.beginning_of_week          # => Mon, 03 May 2010
+d.beginning_of_week(:sunday) # => Sun, 02 May 2010
+d.end_of_week                # => Sun, 09 May 2010
+d.end_of_week(:sunday)       # => Sat, 08 May 2010
 </ruby>
 
 +beginning_of_week+ is aliased to +monday+ and +at_beginning_of_week+. +end_of_week+ is aliased to +sunday+ and +at_end_of_week+.