I don't understand how the darkness part of entrainment works. I'm in mediterranean, daytime duration ranges from roughly 16 hours in the summer to just under 9 hours in the winter. If that had major influence, it seems like it would just be messing the rhythm up.
But then, if it's only (or mostly) about morning sun exposure, daylight sav…
I don't understand how the darkness part of entrainment works. I'm in mediterranean, daytime duration ranges from roughly 16 hours in the summer to just under 9 hours in the winter. If that had major influence, it seems like it would just be messing the rhythm up.
But then, if it's only (or mostly) about morning sun exposure, daylight saving time would not be such a big deal (if you don't wake up at sunrise, which I guess most people don't?). The clock shifts, you wake up with an alarm clock an hour earlier, and then you immediately get sunlight exposure at waking time, just as you would if you traveled.
Maybe I'm out of touch and most people don't actually get up more than an hour after sunrise? But when the clock shifts forward in March, the sunrise is around 5:40 (shifting to 6:40 next day). If you get up at 7, you should be good.
I don't know if it's the combination of sunrise/sunset, but I naturally wake up significantly after sunrise (often 2-3h!) and DST still hits me quite hard. In fact, it seems to hit night owls much harder than morning larks.
One explanation could be that it's technically not "the first sunlight that hits you" in the chronological sense, but in relation to your own circadian rhythm. I.e. if I'm a nightowl and I wake up at 10am, using an alarm to wake up at 5am and getting into the sun wouldn't necessarily help. I would need the sunlight at 9-11am. Similar with sunset. Similar to wakeup, I get tired around 3-4h after sunset. But yea we don't exactly have a ton of data/understanding on how exactly it impacts people at that granular level.
The darkness part is apparently that as soon as your "time receptors" don't receive any (mostly blue) light any more, your body begins to secrete melatonin. The levels rise, and when they've risen enough, you get tired.
It can actually mess things up, although probably less in the Mediterranean than more extreme places further from the equator (where the differences are more pronounced). I think people in the arctic have to sort of induce artificial day/night for themselves when it's always bright/always dark.
> One explanation could be that it's technically not "the first sunlight that hits you" in the chronological sense, but in relation to your own circadian rhythm
That would also be the case for regular jetlag, right? But if the sunset does have a strong influence on you, that could be one of the reason why you have more trouble with DST than with jetlag.
I don't feel sunset influences me at all, I've always been most energetic and focused at night (similar to many night owls). I barely even notice DST (not that my sleep is very good anyway, I had a lot of problems with drifting sleep/waking time. I got it somewhat under control with time-release melatonin, and perhaps simply getting older).
Being energetic/focused at night doesn't mean sunset doesn't influence you. I'm the same way. It could just mean your rhythm means you get tired at sunset+4h instead of sunset+1h like an average person.
Could also be that it's something like the middle between sunrise (or really, first sun exposure) and sunset (or really, first darkness) averaged over a few days?
I'm not sure we know the exact mechanism or have enough granular data to say.
I don't understand how the darkness part of entrainment works. I'm in mediterranean, daytime duration ranges from roughly 16 hours in the summer to just under 9 hours in the winter. If that had major influence, it seems like it would just be messing the rhythm up.
But then, if it's only (or mostly) about morning sun exposure, daylight saving time would not be such a big deal (if you don't wake up at sunrise, which I guess most people don't?). The clock shifts, you wake up with an alarm clock an hour earlier, and then you immediately get sunlight exposure at waking time, just as you would if you traveled.
Maybe I'm out of touch and most people don't actually get up more than an hour after sunrise? But when the clock shifts forward in March, the sunrise is around 5:40 (shifting to 6:40 next day). If you get up at 7, you should be good.
I don't know if it's the combination of sunrise/sunset, but I naturally wake up significantly after sunrise (often 2-3h!) and DST still hits me quite hard. In fact, it seems to hit night owls much harder than morning larks.
One explanation could be that it's technically not "the first sunlight that hits you" in the chronological sense, but in relation to your own circadian rhythm. I.e. if I'm a nightowl and I wake up at 10am, using an alarm to wake up at 5am and getting into the sun wouldn't necessarily help. I would need the sunlight at 9-11am. Similar with sunset. Similar to wakeup, I get tired around 3-4h after sunset. But yea we don't exactly have a ton of data/understanding on how exactly it impacts people at that granular level.
The darkness part is apparently that as soon as your "time receptors" don't receive any (mostly blue) light any more, your body begins to secrete melatonin. The levels rise, and when they've risen enough, you get tired.
It can actually mess things up, although probably less in the Mediterranean than more extreme places further from the equator (where the differences are more pronounced). I think people in the arctic have to sort of induce artificial day/night for themselves when it's always bright/always dark.
> One explanation could be that it's technically not "the first sunlight that hits you" in the chronological sense, but in relation to your own circadian rhythm
That would also be the case for regular jetlag, right? But if the sunset does have a strong influence on you, that could be one of the reason why you have more trouble with DST than with jetlag.
I don't feel sunset influences me at all, I've always been most energetic and focused at night (similar to many night owls). I barely even notice DST (not that my sleep is very good anyway, I had a lot of problems with drifting sleep/waking time. I got it somewhat under control with time-release melatonin, and perhaps simply getting older).
Being energetic/focused at night doesn't mean sunset doesn't influence you. I'm the same way. It could just mean your rhythm means you get tired at sunset+4h instead of sunset+1h like an average person.
Could also be that it's something like the middle between sunrise (or really, first sun exposure) and sunset (or really, first darkness) averaged over a few days?
I'm not sure we know the exact mechanism or have enough granular data to say.