Keep stats on your time.

Try it out on App Engine.

1. all time
2. today
3. this week
4. this month
5. this year
6. this day of the week
7. this 10-minute time
8. this 10-minute time on this day of the week

• minutes up to 24 hours (1440)

1. Timer creates singleton with start time
2. Timer writes end time and..
3. Transactional insertion of reaper task with guid
4. Reaper task updates dimensions 1-8 if guid doesn't match (idempotence)
5. Deletes timer (reset)

Each dimension also records the number of contributing samples, average, median and the standard deviation. Dimensions 2-5 accumulate history (one Datastore entry per day, etc...) Dimensions 1 and 6-8 are singletons and accumulate over the lifetime of the timer.

Timers are namespaced by who is timing and what they are timing. A user cannot run multiple timers simultaneously, even if they are timing different things.