Debugging time-based configurations could be a nightmare, as you have to switch router's time back and forth trying to debug your configuration and wait for the desired event to occur. When I was debugging my EEM-based solution to time-based BGP policy routing, I simply defined two aliases that would set the clock to 30 seconds before the event I wanted to test:
alias exec 859 clock set 08:59:30
alias exec 900 clock set 09:00:30
Obviously, these tests are best done in a lab setup … and you have to turn off NTP or any other form of time synchronization.