Hi. Sorry for title-gore, not sure what better title to use.

I was thinking about how tagtime gives you the right answer “eventually”. So, say I want to know how much time of my life goes to reading. In 10 years of tagtime I’ll have an amazingly close estimation of the portion of my time spent reading books. I believe this makes sense.

The problem comes if you want to know how much you sleep, or exercise, or waste time on social media, or a wide number of such behaviours that change over time.

In 10 years you will know that you slept 27375 hours total, or 7.5 hours a day. Oversimplifying how sleep works, that could either mean that you sleep a good number of hours, or that some months when you’re overworked you sleep 4 hours a day and some months when work is slow or on weekends/vacation you sleep 11 hours a day, in equal proportion. Still comes out to 27375 hours!

You could zoom in to see what happens each month, except of course you’re not necessarily going to switch sleeping habits *on the month*, or hard-switch one day from one sleeping schedule to the next.

So:

- What’s the smallest time interval “chunk” you can analyze and hope to be covered by the “will eventually be accurate” guarantee?
- How do segment time intervals to find changes in behavior/time spent on things?
- How do the above, mathematically, depend on average ping interval and proportion of tags being the one you’re interested in analyzing?
- that proportion is time-varying, which is the whole reason we’re interested in this; can math save the day anyway?

What am I missing? It seems to me that without some further math and thinking, tagtime can’t deal with “how much sleeping are you doing” *over time*, it can just deal with “over the whole period you’ve been tagtiming, you spent 42% of your time on foobarbaz”.

The only “hack” (?) that comes to mind given my zero mathematical sophistication is, given time * T* and a window

*, the total time*

**W***spent per day at time T is the*

**S*******

*number_of_pings**/*

**pings_per_one_day***, with an error bar that depends on*

**W***and*

**W***(which I don’t know how to calculate but I’m sure you folks do). you can then plot*

**S***against*

**S***.*

**T**