Nap hours per day

Here’s a pretty good one: the number of hours that I tagged “nap” in my timesheet.

Here’s the definition of the “nap” tag:

  • Sleeping that happens after the first wake of the day (when I get out of bed from the previous night’s sleep), and after the daily wake time (8am)
  • Not: oversleeping

Like in the traveling time plot, the blue trace is the raw data, and the red trace is a 7-day moving average.

The moving average looks periodic, and I don’t understand why. FWIW, I thought it might be an artifact of outliers, so I switched the moving average to a moving median - but the same trend shows up.