Tracking my sleep behavior in spring

For the three-month period of April-June 2012, I recorded the time of day I woke up and went to sleep. I was curious to see whether my actual sleep habits matched up with my perceptions of my sleep habits, and whether any interesting trends could be found in the data.

This is the graph of the time of day I woke up (blue line) and time of day I went to sleep (red line). I typically woke up between 8:00am and noon, and went to sleep between midnight and 4:00am. The upward spikes every weekend are very apparent.

The earliest I woke up was at 6:59 AM, on Saturday, April 7, for the Stanford CS Section Leader road trip known as BAWK, where every day consists of at least 10 hours of driving. This was the only weekend I woke up earlier than the surrounding weekdays.

The earliest I went to sleep was 9:45 PM on Thursday, June 21. I had attended the Pride-themed NightLife at the California Academy of Sciences, drank too quickly and got tired.

The latest I went to sleep was Thursday, May 17 on 10:15 AM the next day, after the Facebook all-night Hackathon that preceded our IPO on May 18. The latest I woke up, at 3:00 PM, was a tie between May 18 after the Hackathon/IPO, and Sunday, June 10, where I was in Vegas for Electric Daisy Carnival – appropriately organized by Insomniac Events.

This graph shows the average wake-up time (blue line) and sleep time (red line) for each day of the week. No surprises here: I wake up and go to sleep later on the weekends, and my sleep habits are most consistent mid-week, on Tuesday and Wednesday. What’s interesting is how the average deviates from my perception. On a typical weekday in this period, I set my alarm for 8:50 AM to get on a 9:30 shuttle to work, and planned on going to bed at 12:50 AM in order to get 8 hours of sleep. But a “typical” day is actually on the early side; most days that deviate from typical behavior tends to start later – sleeping in and getting on a later shuttle after cramming on a work deadline past midnight, or going out.

This is the graph of the number of hours awake in each day (blue line) and number of hours asleep in each day (red line). Again, let’s look at the extremes and see what stories they tell.

My longest day was 24 hours, 40 minutes long, on Thursday, May 17, for the Facebook Pre-IPO Hackathon. Admittedly I might have napped a little bit during that time. My shortest day was 10 hours, 15 minutes long, on the day after, Friday, May 18.

My longest night of sleep was 11 hours, 0 minutes, on the night of Thursday, June 21, following my unexpectedly early bedtime after NightLife. And thank goodness for that extra sleep, as only two nights later, on the night of Saturday, June 23, I had my shortest length of sleep, at a mereĀ 2 hours 10 minutes. I went to sleep after a long night of San Francisco Pride festivities, but had to wake up in time to march with Facebook in the Pride Parade. I got lots of help from caffeine.

This graph shows the average length of day (blue line) and length of sleep (red line) for each day of the week. Even though I aim to average 8 hours of sleep every night, a quick glance at this graph tells me that number is closer to 7.5 hours. It’s curious that the blue line has an upward slope while the red line stays relatively flat – it appears that I shift my sleep schedule forward about 20 minutes every day, and then snap back 2 hours on Sunday night.