A timer that measures the percentage of an activity’s duration that has elapsed or is remaining. User enters an activity name (e.g. School Day or Work Day) and schedules the activity duration by entering a start time/date and an end time/date. Timer starts at the designated start time/date. The percentage of the activity’s duration that is over, along with the time remaining is shown in numeric and graphic form. Alternatively, the user can choose to see the percentage of the activity’s duration that is left, along with the time elapsed. Multiple timers can run simultaneously.