Extract Utils#days_in_month to delegate to Time

lib/montrose/rule/day_of_month.rb

@@ -23,7 +23,7 @@ def include?(time)
 
       # matches days specified at negative numbers
       def included_from_end_of_month?(time)
-        month_days = Time.days_in_month(time.month, time.year) # given by activesupport
+        month_days = ::Montrose::Utils.days_in_month(time.month, time.year) # given by activesupport
         @days.any? { |d| month_days + d + 1 == time.mday }
       end
     end

lib/montrose/rule/day_of_year.rb

@@ -30,7 +30,7 @@ def included_from_end_of_month?(time)
       # If no year is specified, it will use the current year.
       # https://github.com/rails/rails/pull/22244
       def days_in_year(year)
-        Time.days_in_month(2, year) + 337
+        ::Montrose::Utils.days_in_month(2, year) + 337
       end
     end
   end

lib/montrose/utils.rb

@@ -59,5 +59,9 @@ def day_number!(name)
       day_number(name) or fail ConfigurationError,
         "Did not recognize day #{name}, must be one of #{DAYS.inspect}"
     end
+
+    def days_in_month(*args)
+      ::Time.days_in_month(*args)
+    end
   end
 end