28h Days: year 1 update(sidhion.com) |
28h Days: year 1 update(sidhion.com) |
Neurobehavioral Performance in Young Adults Living on a 28-h Day for 6 Weeks
https://en.m.wikipedia.org/wiki/Polyphasic_sleep
I never actually tried it from what I remember. Cool to read someone’s experience with it.
Uberman's sleep schedule - every 4 hours, sleep 20 minutes.
https://everything2.com/title/Uberman%2527s+Sleep+Schedule
Everyman sleep schedule - per above, with an additional 3-hour nap each 24 hours.
https://everything2.com/title/Everyman+Sleep+Schedule
Of course, the surest way to experiment with an alternative sleep schedule is to simply take care of a newborn, something humans have gotten pretty good at over the millennia.
I guess the only other things I would want to know is what factors pushed most to switching schedules? How long do you plan to stay on the schedule? How does your employer handle this schedule change? Or are you self employed/running a business? What do you think the biggest challenges are during the switch aside from being tired at hour 10-11? What does your SO really think about this schedule? The more I think about this, the more questions I have :)
On a >24 hour sleep schedule, you _will_ be tired when it's time to sleep. Guaranteed. Not only that, you can sleep longer and will always feel well-rested.
Meeting people all around the world, when they're collectively hanging out online, is also fantastic. Social platforms that involve more one-on-one contact, like X, Group chats, and similar, have completely different things going on at different hours. You start to make even more friends spread out across the world, and prevent getting stuck into ruts.
There's also the benefit that conversations and the environment online is always fresh. You're always cycling into new time blocks that you haven't been active in for a few days.
And, not just online. There's something to be said about experiencing (while fully awake) all of the different times of day where you live. You get to see sunrises and sunsets. Busy morning chatter of cars, and the world buzzing to life. The beyond-wee hours of the morning, when the city is so quiet you can hear a pin drop.
Really though, the main benefit is the first one in this comment. You can live your life to the maximum extent, without scheduling in the extra time to manage getting to sleep, and feeling tired when you don't.
OP is likely able to do this because they have a longer circadian cycle (though I think it's still less than 28 hours)
A person who might naturally have a 24.4 hour cycle without external stimuli (which is the average sleep researchers found) will likely have problems trying to adjust to a 26 hour cycle or longer, because even if they push themselves to stay up beyond the beginning of the sleep phase of their cycle on a regular basis, there is a good chance they'll wake up closer to the end of their sleep phase, and therefore might not get enough sleep.
It's better to follow a sleep cycle tailored to your own circadian rhythm, which for most people conveniently aligns pretty well with the natural day.
I say this as someone with non-24 who often does free-running sleep (where I've found my own cycle to be a little over 26 hours in winters, and closer to 24 hours in the summer)
Definitely not guaranteed at all. Many people’s circadian rhythms are intensely driven by daylight cycles. Trying to sleep and wake out of sync with those cycles will be very difficult.
In the past I had to do some work overnight which resulted in some very long days. I would have to be very careful to avoid seeing the sunrise because doing so would make it very hard to sleep even if I’d been up for a long time.
> Really though, the main benefit is the first one in this comment. You can live your life to the maximum extent
If your life involves a lot of solitary, indoor activities then maybe.
For the rest of us who like to socialize and do outdoor daytime activities, having your sleep schedule cut through daylight hours would be a big step backward.
I think people greatly overestimate the benefits of alternative sleep cycles (unless you have a naturally extended circadian cycle that can’t be otherwise managed)
I did this for a year when I was caring for my dad and working at the same time, but remember that this process makes you almost completely alone because your breaks do not line up with the world around you.
I would wake up at 7 AM on a monday, to attend the weekly planning meetings & keep slipping by about 1 hour every day of the week, so by Thu I am waking up after noon & I tended to just work through the night on Fri to sleep near dawn on Saturday.
The problem was that Fri nights and weekends are when people are mostly ready to socialize or relax, I would literally sleep through the day on Saturday and wake up close to 4 AM on Sunday.
Then go to sleep around 7 PM on Sunday, because I woke up so early and then monday I wake up with 12hours of sleep.
Lost weight from skipping meals by sleeping.
This felt completely awesome from a personal standpoint & also from the friends I had on IRC, but from an IRL standpoint it was very odd.
I definitely looked like a shut-in, even I grew my hair out simply because I did not have the time to go get it cut during business hours.
Then my dad died, which ended that chapter in an unexpected way.
I remembered those days when I had my first kid, the experience was shockingly similar when it comes to perturbed sleep schedules.
EDIT: just read the original post[1] from the author and indeed this is the reason. He maybe explains it better than me so give a read.
>Some time ago, I found myself with zero obligations to follow the usual daily routine: wake up in the morning and go to sleep at night (the “normal people schedule”). During my time awake, I was either working on side-projects or playing with my hobbies, and I’d go to sleep whenever I felt sleepy, wake up naturally (no alarms), and repeat. This led me to observe that without sticking to a daily routine, my sleep schedule would drift every day compared to the previous one. I also noticed that on most days I’d sleep a bit longer than 8h, sometimes 9h or even 10h.
>An example of the sleep schedule drift: if on day X I went to sleep at 10:00 and woke up at 18:00, on day X+1 I’d go to bed at a time later than 10:00, and wake up later than 18:00. I almost never went to sleep at the same time on two consecutive days.
>I realised that this was happening because it took me longer to feel tired than the “normal people schedule” assumed. If I followed it, sleeping would tend towards napping until the tiredness built up, at which point I’d need to sleep more. In fact, for most of my adult life (especially when I had a full-time job), I’d always have to force myself to go to bed during weekdays, and naturally this drift would occur, and then I’d “reset” during the weekend (often 10h+ of sleep), thus going back to forcing myself to sleep on weekdays to stick to the routine.
This one of the bigger myths around. There's not really scientific evidence that people sleep eight hours, or need that much[1]. It's one of those strange pop culture food pyramid like statements that just doesn't really have any evidence for it. It's much more likely that you simply need less sleep than that you have some circadian rhythm problem.
[1]https://www.penguin.co.uk/articles/2020/09/daniel-lieberman-...
Showing my age here but...
I and some of my friends/classmates used to do the 6day 28hr cycle, to ensure we had access to the computer lab where "normal people" were asleep during the week, but were still mostly "in phase" with everybody else on weekends for socialising.
For those of you who don't understand the term "computer lab", those were the days where my Comp Sci class involved writing/running Pascal code on a shared VAX-11/780 which (from memory here) shared 64MB of memory across all users of the 100 or so terminals attached to it. During the day, especially close to assignment deadlines, there were often long wait times to get one of the terminals. If you were there (and awake) at 10pm or 4am, there was usually only a handful of other people using it, with no waiting queues and with noticeably faster performance.
(When I started 2nd year, the first year class behind me still learned Pascal, but got to use the new Macintosh lab. That kinda made the 28hr phase shifting unnecessary, but a bunch of us persisted anyway. By 3rd year, the VAX was under-utilised enough that they added a bunch of modems, and I could connect from home via a 1200/75 baud modem from the Osbourne1 Z80/CPM machine I had at home.)
The main challenges were two-fold. First, there is a significant part of the time where it doesn’t line up with store and restaurant hours that well, which is inconvenient. Second, there are few days every couple weeks where your schedule is completely out-of-phase with normal people which makes socializing nigh impossible on those days e.g. waking up at 8pm and going to bed at 2pm. However, since those days were predictable, I’d simply not schedule anything on those days.
I don’t think this really works for a global business though. Many people around the world are really fussy about rigid schedules, and you will only overlap those a third of the time.
All that said, I think for >24 hour days to be practical, it would be best in a synthetic environment where everyone is on the same clock with limited access to natural sunlight. I could totally imagine it being viable for something like a submarine.
It was pretty wild. I coded (machine code) in bed until my head got heavy then I would nap and wake up shortly after with the task noticably organized in my head. It felt perfectly natural to sleep on it as well as to wake up when the data was parsed. I kinda lived in the twilight zone.
Fun details: the room was perfectly dark. The tv was set to be so dark that I had to wait for my eyes to adjust to see the code. Nothing else was visible. The bed was tilted about a foot. The computer had no mouse pointer.
I do this at least from 10 years without bad effects, the positive effects are that I'm more awake and feel fresh longer, in control of my mental power.
It is quite easy to do it while having normal life obligations, I can wake up sooner if something needs to be done, and then, after the task, I can continue to do my day until sleepy, at which point I can sleep again. So, if I have many meeting on a day, I can stay up all day without issues, maybe I'll sleep more in the evening or following day.
I think the quantity of sleep I require depends on the tasks I'm doing. If some task is particularly mentally exhausting I'll automatically do more naps during the day, this in turn makes me more efficient at solving difficult problems.
It is extremely comfortable to solve hard problems in this way, when you work too long on it, you get sleepy, and as you wake up, you are again fully focused and with fresh perspectives.
Also if people cant respect or don't like your lifestyle, I don't see a point in being with them. If they cant move things around or if we cant find time for something, move on. Life is too short to deal with people problems that can be solved just by doing nothing.
I knew of a sysadmin who followed this schedule so he could monitor the system at different times of day. There’s probably the same upside for people who manage certain 24-7 operations (though the downsides outweigh them in most cases).
This was just the 1 year update.
Idea is that you go to be when you feel tired.
Countless times in my life I have lived 26-28 hour cycles and otherwise I am in a never ending struggle to live a 24 hour cycle. Once I hit retirement I will definitely try this 28 hour cycle and might even switch to it permanently.
Yeah there are obvious downsides having to do with SO, friends, etc. Having a husband with this same biological quirk would be ideal, but again once I no longer have to go into the office it will be really hard not to fall into a > 24 hour pattern.
Not usually, no. Typo?
One of the common themes was that people would think their lives were better at first. A sort of placebo effect. They’d push through the adaptation phase, which was miserable, and when they adapted they felt slightly better. Often this improvement (relative to the miserable adaptation period) was mistake for an absolute improvement because it had been so long since they had a normal sleep schedule.
What was really interesting was that most people reported some variation of the same thing: They didn’t realize how much they disliked the alternative sleep schedule until after they stopped it. Some people stuck with it for a long time until life forced them to change (job, marriage, etc). It wasn’t until they went back to normal that they realized how much better it was to just not fight the sunlight and night time that drives us.
It would be interesting to see how this person feels at some point in the future if they go back to a normal sleep schedule.
Only one note: OP sounds like a younger person, probably in their 20s. My body was able to take some serious abuse when it came to sleep schedule back then. I had a job that kept alternating between 2-3 day shifts, then 2-3 night shifts, then 2-3 days off. Sometimes I’d not go to sleep for 24+ hours.
I’m twice the age now, and I’m still paying for it. My sleep is not great. I have to be very responsible with sticking to my schedule, and waking up anytime after 3 a.m. results in an inability to fall asleep and a day-long headache.
When I was young, I could stay up for 26 - 30 hours regularly without any issues, even on multiple consecutive days. I would be fine no matter how I slept.
No more. If my sleep schedule gets disrupted in any way, too short or too long, my body will immediately go into "things are not right" mode.
So a typical schedule could look like:
10pm-2am - sleep
2am-10am - awake
10am-2pm - sleep
2pm-10pm - awake
I've experimented with this a lot - for whatever reason, I don't know why, this split schedule allows me to feel much more alert and attentive during my waking hours, and isn't as stressful as trying to sleep a full 7-8 per night which a lot of times feels impossible for me.
Sometimes I'll do 5-6 hours sleep on 1 cycle instead of 4, so it can shift around, but otherwise stays pretty consistent. Technically I am getting just as many sleep cycles as a "normal" schedule (One part of this was a sleep study to figure out what my natural full rem cycle is, for me, it's about 2 hours long).
I've been doing this for about 2 years and wouldn't do anything else, and it's really not difficult to fit it into a "normal" routine. My close friends have remarked that it makes it seem like I never sleep (due to being available at hours all around the clock), that's about all that anyone has remarked about it.
I got plenty of rest and got all my domestic stuff done overnight - 24h grocery store, laundromat, etc. I was never unusually tired.
The down side is that it mostly killed my social life. So I quit; the advantages didn’t outweigh the disadvantage of being on a different schedule than everyone else.
Also this was in the late 80s/early 90s before cell phones and the internet.
That's pretty common for crew on yachts. I'd do that when racing or cruising ocean going sailboats. The crew gets split into 3rds, and everybody gets to do a 4 hour night watch. (For racing for me, that'd usually be only for a few days or a week tops. I twice spent ~6weeks on that schedule cruising the Great Barrier Reef.)
Which is a shame because longer days would probably significantly improve my sleep.
That said, avoiding having to do that again was a big motivation in getting out.
I hope it's not too personal to ask, but I'm wondering how that is working out with the SO.
My own experience thus far, as someone whose body by default seems to want to do 25-26 hour days (and can do much longer when I choose), is that an SO is one reason to force myself to stay on a 24-hour cycle.
If you're both doing grad school, hospital shifts, startups, trying to make partner, traveling a lot for work, etc., then having your schedules not always overlap might come with the territory, and you both can adapt. But if they find they're often wanting to spend meaningful time with you after their work, and you're sleeping during normal-person waking hours, they might be wondering whether this is the right long-term relationship.
They were much more natural to me than a 24 hours day length.
If I ever win the lottery, I just may sail endlessly west to east...
Now when I'm not able to just sleep and wake up completely naturally it always sucks following a more normal schedule of going to bed around midnight waking up around 7.
So I try to prioritize the biphasic sleep with the idea that the stages are variable. As in sometimes I sleep through all 3 stages, sometimes I stay up after the first time I wake up, or sometimes I don't initially fall asleep until the last stage.
I find that my days don't fit a 24 hours schedule either, but I don't feel like they fit the same set amount of hours each day at all.My motivational and energy levels are just different depending on the day and have a wake / rest cycle that can fit with that is beneficial.
So, I might actually try this.
If you are, then you're likely adjusted to the 24 natural cycle and something else is going on. The closest thing I'm aware of is https://en.wikipedia.org/wiki/Irregular_sleep%E2%80%93wake_r...
Overall - I don't regret it, and if you're someone who likes to try different life experiences, give it a shot! But I'm not going back anytime soon :)
I just checked the dates and it was 20 years ago. Soooooo old....
Yet lines like this just seem really tongue-in-cheek:
> In fact, I avoid talking about the schedule at all with others.
> The internal benefits more than make up for the slightly trickier external interactions.
> I don’t keep track of this in any scientific way, only mental notes that I make along the way
> There might be some longer-term changes, mostly associated with my health, but if these exist, they’ll likely start showing up in the next few years. We’ll see what the future holds.
So I'm very much with the author here and I might actually try 28-hour days because what I have for the last 10 years is a mess.
Are you not getting much sunlight? I can understand the reaction to being told something that doesn’t match your experience. But. The link between sunlight and sleep for most life on earth is pretty well established science, and has a name: Circadian Rhythm.
Have you ever tried camping for a week? My sleep tends to drift when I’m working indoors a lot, up late at night a lot, during winter, etc. But if I spend multiple days outside, it starts to align with sunrise almost immediately.
Both of these links say that Circadian Rhythms tend to drift and be longer than a day on average in the absence of sunlight.
For the few weeks that I'm required to go back to a "normal" sleep schedule, I long every day to go back to my 28h schedule.
I might at some point in the future try moving back to 24h for a longer period of time, but I'm planning to stick to the 28h schedule for at least a couple more years before I do this, and I'll keep doing the yearly updates to document things.
I always try to dissuade people from it. It's difficult to get into, and difficult to maintain. It plays hell with a social schedule where people expect you to be awake at certain times.
No one is selling anything. There are many of us who benefit remarkably from what you're calling an "alternative sleep schedule" (I'm not specifically talking about 28-hour day entrainment like the blog author, but whatever works for each individual based on their own idiosyncratic circadian rhythm)
Many of us have periods where we have to go back to 24-hour schedules due to external factors, and sleep quality and duration suffer as a result. For myself, in the winter when my schedule is a little >27 hours, when I enforced waking up at 8 AM Monday-Friday for a 9-5, my schedule might go something like this:
> Sunday night: Sleep 7-8 hours starting at midnight.
> Monday night: Sleep 5 hours starting ~3 AM Tuesday.
> Tuesday night: Sleep 2-3 hours starting at ~5 AM Wednesday. Sometimes with exhaustion I may then be able to fall asleep at 5-6 PM (Wednesday) but often would stay up til closer to midnight-2AM. Regardless, when I fall asleep I likely will wake up in 1 or 2 hours and be unable to go back to sleep, as my body doesn't believe it's in the sleep phase.
> "Wednesday night?": There isn't really a Wednesday night except on the occasion where I managed to sleep more than 2 hours. Sometimes I'm up all night with no nap; more than half the time I can't sleep more than 3 hours. Occasionally I'm actually able to stay asleep during what my body thinks is a nap to pay off sleep debt.
> "Thursday night?": Exhausted from having slept no more than 9 hours in the last 48 hours, and usually closer to 3-4 hours, I'll collapse around 5-7 PM from exhaustion and sleep until midnight-5AM.
> "Friday night?": Often I'm ready for sleep by 5-8 PM and will sleep 8-9 hours. But I'll also occasionally try to sleep less and push myself to go out at 9-10 PM if there's an event happening. After being more active and if I slept less than 4 hours I can usually pick up another 1-3.5 hours of sleep after 4 or 5 AM.
> Saturday night: If I got a full night's sleep, or went out Friday but slept a little bit after, I may be more energized, so this is the more consistent day for weekend plans. If sleep was poor I'll try to sleep an hour or two early in the evening before going out and then sleep 3 AM to 9 AM or so. If I didn't have Saturday plans I may go to sleep at 8 PM and sleep til 5 AM.
> Sunday night: Usually fall asleep somewhere around midnight but who knows? I could be up til 3 AM depending on how the weekend went.
All told I would probably get an average of ~5.5 to 6 hour of sleep per 24-hour day, but with significant periods running on very little sleep.
Now that I work from home and have few meetings, my schedule may look more like the following:
> Sunday night: Sleep from midnight to 7 or 8 AM
> Monday night: Sleep from 3 AM (Tuesday) to 10 AM (in time for my 10 AM Tuesday meeting).
> "...": Sleep Wednesday from 6 AM to 1 or 2 PM (Wednesday)
> "...": Sleep Thursday from 9 AM to 4 or 5 PM. Stay awake for my 10 AM meeting Friday.
> "...": Friday I have a meeting from 10-11, then often coordinate with coworkers til noon, but as late as 2 PM (rarely later). So I sleep after and wake up any time friday from 7 PM to 9 PM, go out feeling relatively well-rested.
> "...": Saturday if I have plans I take a nap then go out and fall asleep around 3 AM until 10 AM.
Sunday I probably won't be able to sleep at midnight. Tuesday my 10 AM meeting this week will probably interrupt my sleep phase, but I can usually go right back to sleep after.
All in all on this schedule I get longer periods of uninterrupted sleep, get an average closer to 6.5 hours of sleep per 24-hour period, and never have periods of 48 hours where I only sleep 2 hours, so my overall energy and focus over the week is much better.
I imagine an app which populates Calendly or Google calendar (booking appointments) with times when you're asleep.
Not saying non-24 is good for you, but for people unable to follow a 24-hour schedule, free-running sleep (which is what OP is doing) is vastly better than constantly pushing through sleep deprivation, when one's schedule allows for it.
Speaking as someone with non-24 myself (which is much more severe in the winter)
edit: after reading more closely, it appears OP has entrained to a 28-hour day rather than doing free-running sleep; 28-hour days are convenient in that the week gets sliced into 6 days and allows for a consistent weekly schedule. However, I suspect OP actually naturally gravitates towards a shorter day like 26 or 27 hours based on their napping patterns. I also wonder if they might even have more success with 24-hour days and regular exercise, as from their description it almost seems like the daily exercise practice which they started after the 28-hour day might be regulating their circadian rhythm to be closer to a natural day.
[1]: https://en.wikipedia.org/wiki/Non-24-hour_sleep%E2%80%93wake...
I remember so many people in my life being skeptical about my claim that I naturally have longer days than 24h. Then ~6 years ago I actually tested it; my watch recorded my sleep, and it became obvious:
https://photos.app.goo.gl/rTh2vkEMPEiJXx5Y7 [time-asleep graphed on a daily 24h chart]
And only then did I learn what a non-24 was.
I exercised regularly before 28h days, and my sleep was still chaotic with that. I didn't exercise daily though, it was hard to fit everything I wanted to do on a 24h day. Having longer days means I can fit more things, which I think is one of the reasons why I increased the amount of exercise after moving to 28h.
I also haven't read any research on this, I just did what felt more natural and logical to me.
That's exactly what this pattern is trying to avoid. For people whose sleep cycle is longer than 24h, a "normal" rhythm makes every single day a jet-lagged day, and in the "wrong" direction (it's easier to travel west/stay awake longer rather than travel east/go to bed earlier for most people).
Human body can be really bad at adapting to unworldly environments to the point you totally break down.
I don't see anything problematic with TFA's 28-hour days.
A few months ago I finally got a CPAP machine after getting a sleep study due to abnormal blood pressure patterns (my blood pressure wasn't dropping overnight on a 24 hour monitor). I can now wake up feeling alert and ready to go after 6 hours of sleep (even though I could use a little bit more); I haven't felt rested this way in the morning since more than 15 years ago in my 20s. I'm not particularly overweight, nor do I snore, so it's worth checking into if your sleep patterns tend towards abnormal.
You seem oblivious to the decades of research into chronobiology and studies into shift work, jet lag, etc.
Your loss.
Fewer hours asleep means 2 more hours awake.
The thing with taking a similar test every day is that you should get better at it. So if the test you are abusing shows that your cognitive function is holding steady day by day, week by week, that is likely not a very good sign. It just means you aren't unraveling at an alarming rate. Better to be evaluated by professionals at the beginning and end, and maybe for some people who already know you to chime in on how unhinged you have or have not become.
In the winter I can do 12 hours pretty often. It's not always but every few years I get a few weeks or months of 12 hour nights.
I love sleep.
Non-24-hour sleep/wake disorder is not something one can fix like this. I would if I could. I've had this problem since my late teens.
https://en.wikipedia.org/wiki/Non-24-hour_sleep%E2%80%93wake...
Probably a contributing factor to difficulty in getting to sleep "at a good hour".
OTOH mild sleep deprivation has been shown to counter depression, so there's that.
Even after we accept that a dichotomy like typical vs atypical (or night owl vs morning lark; omnivore vs vegetarian) is way too simple.. the more we look the more we keep finding new “types” (like all the flavors of non-24; vegans, paleo, etc). So even reading stuff that’s trying to be rigorous may ultimately just tell you about fads and fashions that might be working for others. Natural variation in people seems to outpace or defy our ability to categorize stuff. To me this hints that there’s really no substitute for experimenting and listening to your body.
The hard part is just that this does require some time and space in your life to accomplish, because if you’re going back to basics about stuff like food or sleep then inevitably it’s going to be disruptive until you figure out what works best.
There are some good references in the wikipedia page (https://en.wikipedia.org/wiki/Non-24-hour_sleep%E2%80%93wake...), and I've been following https://reddit.com/r/N24 for a while also.
Some people with non-24 have very regular sleep/wake cycles. I'm not as fortunate, but in the winter will tend towards 24-29 hour days, with an average just over 27 (perhaps this winter has even been a little under 27 as I've been more physically active)
In the summer it's close enough to 24 hours that I can stick to a 24-hour schedule most of the time.
Without external stimuli, it’s very hard to avoid drifting into staying up very late at night for me.
You need a significant period of time without any time-bound obligation (or even any obligation at all). Any need for an alarm or anything that you'd possibly materialise in a calendar needs to be removed.
You need a room which is pitch black at night (e.g blocks street lights, no leds), yet still allows a tiny bit of sunlight (rationale: without cues the circadian cycle extends up to 48h, there was an experiment about that)
Then, once you have that, start freewheeling, just when you feel tired go rest and when you wake up get up. It'll be a mess at first, for two reasons.
First you may be unable to properly recognise the "I need to take some rest" signal: we're trained by life to largely ignore it.
Second, you need to pay off any debt, sleep, physical, mind, that would play a role in altering your base cycle. Have fun, work out, meditate, go see a therapist even. In a nutshell, find your balance.
Once you have recovered from everything, once all biasing sources have been removed, then sleep will converge to some rhythm, which carries some error margin, so you can only observe it statistically over time. There's your baseline.
It could take months, which more often than not isn't practical to have, so from the above ideal scenario one could devise a protocol that would try to stick as close as possible to it.
Source: first principles+anecdata, sample size of 1, double-non-blind protocol; a.k.a myself digging out of a hole.
Protocol: 3 week sick leave for burnout x anxiety depression, coincidental breakup (so no SO), went from office to remote working, workout plan, 6 month therapy, statistically reliable sleep/health/performance tracking via watch allowing for outlier identification/retrospective deviation root cause analysis.
Result: 0130-0930~30min sleep, 7h45min~5min sleep duration made of two ~4h-ish blocks, 25h~30min cycle. When bound to 24h rhythm, occasional sleepless night leading to 48h day and three aforementioned blocks of sleep (~11h-ish total).
From the data it became painfully obvious that I experience delayed sleep phase disorder, took me 6 months to figure the baseline out, and 6 more to confirm, which is quite hard when you don't even know that it is a thing.
Do you have a link to this experiment? I haven't seen this mentioned anywhere. Studies referenced in the non-24 wikipedia page suggest natural circadian rhythms typically range from 24-25.5 hours for people not getting external cues.
https://en.m.wikipedia.org/wiki/Michel_Siffre
Here's an interview on the subject, which includes the initial experiment (which had him having a slightly over 24h rhythm) and subsequent ones (where the 48h rhythm showed up)
https://www.cabinetmagazine.org/issues/30/foer_siffre.php
The interesting thing about going down a cave is that it removes a ton of other possible cues like temperature variation (or side effects of trying to mechanically account for that)
My pet theory about human beings generally having slightly longer than 24 hour circadian rhythm is that it gives margin: with a 24 sun cycle and a 24.5 rhythm you naturally get a self-correcting consistent positive benefit; otherwise you'd always be right on the edge and unable to recover when things go sideways.
I take melatonin (0.2mg via a spray). It is very effective. Nightmares are a recurring problem for me and other users I know, but can be solved with low doses and a lot of discipline.
People with non-24 usually have a longer than 24-hour cycle and can't "make themselves" go to sleep consistently at the same time (people with 24.5 or 25-hour days probably have some success with this though because if they stay up a bit later one day and still wake up at the same time, then by the time a proper bedtime rolls around they'll be close enough to their the sleep phase of their cycle, and tired enough to fall asleep at that time)
Either way, it seems like a arbitrary distinction to make. If Bob is happier and more productive on a 26 hour schedule, but can unhappily live on a 24 hour schedule, why doest that count?
It seems the relevant Factor is what their natural schedule actually is, given the circumstances etc
You can't do this and raise a child¹ without being, well, an asshole. He would force the mother to do all the fixed daily things, and the child to navigate your availability using your private clock.
1: After they've settled into a stable daily sleeping rhythm of course. For a baby this system might even be useful some nights (but not others).
I can see it going the other way, where if your natural rhythm is 22 hours you can likely force yourself to stay awake to align with 24 (and likely would be much happier than free-running on a 22-hour clock).
Speaking from personal experience, if I could consistently stick to a 24-hour schedule, I would. And I think most people with non-24 have the same position (and have likely tried many things before giving up, as tossing and turning for hours every night and then still not sleeping enough is pretty unpleasant).
Additionally, if Bob's rhythm is 26 hours then his sleep cycle is shifting ahead by 2 hours every night regardless of when he falls asleep. If he is able to fall asleep at the same time every night, his sleep cycle presumably isn't shifting, and even if 26 hours might be more natural for him, he's able to sync his cycle to 24 hours regardless.
So I don't think this would qualify them for non-24, as the circadian rhythm isn't shifting every day.
On the other hand, if Bob chooses to sleep 26 hours for whatever reason, perhaps he could be said to have it then? It's just inconceivable to me that someone would actually choose that given the option.
It's worth noting that the average human circadian rhythm is closer to 24.5 hours when external stimuli are removed. So it doesn't strike me as too different from Bob; people are nevertheless regulated to 24 hours by daylight and not said to be non-24, even if, like Bob, their natural state might be to sleep more.
Bob might go to sleep the same time, but maybe he gets 4 hours of sleep a night and operates on a deficit all day.
It's repeatable on a 24-hour cycle but miserable
If someone is unable to get adequate sleep on a 24-hour day due to their circadian rhythm misalignment then I believe this is non-24 even if it's because they wake up too early rather then go to sleep too late when trying to keep 24-hour days.