The daily planner in PlanRight allows you to schedule tasks with 15 minute increments during a day.  

To plan a day, simple click on the day heading to drill into the daily planner.  The daily planner works just the same as the weekly planner, except that you are now planning in hours instead of days and you can view 1, 2 or 5 days at a time, instead of 2, 4 or 6 weeks.