How do you plan your day?

Daylight launches on Product Hunt on Nov 10. It’s a time-blocking app built around the full 24-hour day: give each goal a block from 15 minutes to 8 hours, see how much of the day is left, then compare the plan with what happened. It runs on web, iPhone and Android. Before launch day, how do you plan your day now, and which part of the plan usually slips?