I began tracking my time continuously in April 2015. It is now October 2018, which means that I have been tracking for three-and-a-half years.
When I mention this in talks, people sometimes ask what I’ve learned. I have a few standard stories I tell, about work hours, reading time, and time in the car.
But here’s another epiphany that is having a surprisingly big impact on my life: I don’t actually need 8 hours of sleep.
Before anyone thinks that I am suggesting skimping on sleep as a productivity tactic — no. Getting the amount of sleep your body needs is important for health and, frankly, getting stuff done. Sleep-deprived people rarely operate at their best.
But how much sleep does one’s body need? This is a different, and very personal question. The “8 hours” figure is so common that this is the number I have in mind for a good night. It is the number I am thinking about when planning my time. Time-tracking has revealed that this probably isn’t the right number, at least for me.
I am not sure why this is so revelatory. I learned very early in my time-tracking journey that I wasn’t, generally, sleeping 8 hours per day. I gravitated pretty strongly to somewhere between 7.3 and 7.4 hours. (7 hrs 18 minutes and 7 hrs 24 minutes in case anyone needs help with the math.) Over any long period of time — like 6 months — this is what my average would be.
At some point I discussed this with my husband — that this was my set point — and he mentioned another possibility: what if this is the minimum my body can get away with? It was possible that I should be getting more (like 8 hours) but if I dipped below 7.3/7.4 for more than a few weeks, that’s when the catch-up impulse would be triggered. I’d be exhausted, go to bed early, nap, whatever.
It’s certainly a theory. After all, for the first 2.5-3 years of my time-tracking, my youngest child was doing his best to make my sleep as disordered as possible. My logs show a lot of middle-of-the-night wake-ups, long after this “should” have stopped. There were bedtime battles (as one example, I recall a horrible night in August 2017 when he would not go to bed until 1:30 a.m. — that’s at more than 2.5 years old). I went through a lot of 4:30 a.m. wake-ups, necessitating naps somewhere in the day, or crashing early.
In the past few months this has gotten much, much better. I worry about jinxing myself but in general, the little guy is in bed by 8 p.m. On the nights I put him to bed, I can read him a story, get him in his bed, give him a kiss and he stays there. Most nights. Not all nights, but most. Even in May I couldn’t rely on that (on Instagram, there’s a selfie of me sitting outside his bedroom, trying to keep him in. We had child locks on the doors but he figured those out). He either sleeps until 7 a.m., or stays in his room until some time around then, looking at stories.
So, for the first time in a long, long time (minus a short window in early 2014) I am setting an alarm that I believe might actually be the thing waking me up.
I need to wake my eldest child up around 7:15 a.m. on week days for everyone to get to school on time. Sometimes I run around 6:15/6:30 in the morning if it’s going to be a busy day, but I’m mixed on that. If I’ll be working at home, I prefer a mid-afternoon run outside. If I want to shower, dress, and have my coffee before I wake up my 6th grader, I need to be up by 6:45 a.m. If I don’t care (and hey, I work from home…I just need to avoid surprise video chats!) then it’s really 7:10.
I turn off the older boys’ lights at 10:00 p.m. So there is a seemingly large window of time — at least 10:15 p.m. to 6:45 a.m. — during which sleep is an option (it definitely beats 10:15 p.m. – 4:30 a.m.!) I can sleep 8 hours. And as a proponent of good sleep hygiene, I have tried to take advantage of this window, doing my best to go to sleep around 10:30 or 11 at the very latest.
But when I do, I wake up before my alarm. Or I lie awake in bed (more rare — I tend to fall asleep relatively quickly).
It makes sense. Looking back on my logs I see that in 3.5 years I have had very, very few weeks featuring 56 hours or more of sleep. I wasn’t always around the little guy. Sometimes I was on vacation away from him. Sometimes I was in hotel rooms. Sometimes my husband was on baby-duty. If I needed 8 hours of sleep, I would have seen more of these weeks. Instead the handful (and I mean just a handful) of 56-hour weeks tended to happen on the heels of 46-hour weeks, nudging me back to the 7.3/7.4 hour average.
The reason this is revelatory is that it’s helped me think differently about sleep in general. Now that I can choose when I wake up (at least within a far more civilized window), I can choose when I go to bed. I can optimize for when I want my leisure. And I can relax a lot more about individual nights too.
In the past I would get slightly stressed about shorter nights. If I needed to wake up at 5:15 a.m. to get to the airport, I’d think it was a problem to go to bed at 10:15/10:30 — because I only had 6.75-7 hours to sleep. I now know that 6.75 is actually closer to 7.3 than 8 is. This night will be fine. Aiming for 7 on a normal weeknight is perfectly acceptable. If I sleep 7 hours for 4 nights and 8 for 3, I’m at 52 hours/week, which is above my set point.
This means that if I don’t want to be up at the crack of dawn — and honestly, most days there’s no reason* — I don’t need to go to bed at 10:30. I can stay up past 11. Heck, if I’m waking up at 6:45 a.m., my actual set-point bedtime would be 11:21-11:27 p.m. I can turn off the lights at 11:30, go to sleep at 11:45, and be fine.
For someone who spent the past three years trying to race into bed after the boys’ 10:00 p.m. lights out, this is very exciting. I can hang out with my husband! I can read another chapter in that book!
It might not seem like getting an extra 4.2-4.9 hours per week to play around with (realizing I can plan to sleep 51.3 – 51.8 vs. 56 hours) would be life-changing, but it kind of is.
How much sleep do you think you need? I think most people are between 6.5-8.5 hours/day averaged over the long term, though some people need more, and some people are short sleepers who require less (though these people are pretty rare).
* Yes, I wrote a book called What the Most Successful People Do Before Breakfast, but no, my natural tendency is not to wake up in the wee hours. Mornings are a great time for getting things done if you have other constraints on your time, like a full-time in-the-office job, or you’re home with little kids and trying to write a novel or start a business. I don’t have either of these constraints. Most week days I view 7-8:30 a.m. as family time as I get the kids up and ready and off to school. Then I start my work day.
Photo: Throwback Thursday shot of the little guy napping, back in the 4:30 a.m. wake-up days.