If you are unsure whether you have created a correct off-peak period
definition, you may use the test utility to check if a specific moment
in time fits into the period or not. In order to run the off-peak period
test, either click the Test
Period icon on the off-peak periods page, or use the Test
Period button on the last page of the off-peak period wizard.
Now simply enter any time / date and click the Test button to check whether this moment fits into the off-peak period definition.