Magento calendar to include hours?

The calendar in the admin of Magento http://www.dynarch.com/projects/calendar/ has the capability to use hours and minutes too. I was wondering if anyone had experien开发者_开发百科ce with modding the calendar's functionality to include hours in the backend of Magento - ie. to being a catalog price rule at 6pm until 11pm.

Any thoughts or pointers on this subject would be greatly appreciated.