new_contents: import pytest
  from unittest.mock import patch
  from unittest.mock import Mock
  
  from examples import daylight
  class FakeDay( object ):
      def __add__( self, other ):
              return other
  
  class Test_Daylight:
      def module_patch( self, patch_module ):
          patch_module( daylight, 'datetime' )
  
      @patch('examples.daylight.datetime')
      def test_Main( self, datetime ):
          fakeDay = FakeDay()
          fakeDay.hour = 12
          datetime.date.today = Mock(side_effect=[fakeDay])
          datetime.datetime.today = Mock(side_effect=[fakeDay])
          datetime.datetime.timedelta = Mock(side_effect=[FakeDay()])
          nextDay = daylight.nextDaylightDate()
          assert nextDay is not fakeDay
          datetime.date.today.assert_called_once_with()
          datetime.datetime.today.assert_called_once_with()
          datetime.timedelta.assert_called_once()
  
      @patch('examples.daylight.datetime')
      def test_EarlyInTheMorningUsesSameDate( self, datetime ):
          fakeDay = FakeDay()
          fakeDay.hour = 2
          datetime.date.today = Mock(side_effect=[fakeDay])
          datetime.datetime.today = Mock(side_effect=[fakeDay])
          nextDay = daylight.nextDaylightDate()
          assert nextDay is fakeDay
          datetime.date.today.assert_called_once_with()
          datetime.datetime.today.assert_called_once_with()
  
subject: add unittest.mock based test to demonstrate differences between Mock() and testix