DST Hot Takes

So as a US American most* of us transitioned into Daylight Savings time last night (well "this morning")... overnight... We jumped forward and hour cutting into our precious sleep time.

This is always controversial because, it sucks. It throws off sleep schedules, messes up your internal clock, etc. But it's great because as the days lengthen it shifts the social clock to be inline with solar time over the spring and summer months, allotting more "daylight hours" to social time.

But, we have to switch back in the winter, and that sucks all over again... So here are my hot takes

Hot Takes

Logistics

Keeping track of time is important. It's useful for logistical reasons. If I want to take a flight from my airport, I need to know exactly what time it will take off so I can arrive 4 hours early and then wait 6 hours as it gets delayed two hours. Okay, snark aside, logistically everyone having the same "time" within a local region helps with this - the flight from LAX is at 5:15pm. And for businesses, the government, etc, scheduling and planning are ever important.

But this is why UTC is so great. You schedule things based off of UTC and then use your local offset to know when YOU need to be there based on your wall clock. But if your wall clock was UTC anyway, you would just show up at the allotted time. And after some adjustment the date shifts wouldn't be so bad. A meeting on "June 5th" may actually be on "June 4th 6PM local" by you.

But this is how a lot of systems actually work. Very rarely, do systems bother with local time, and compute things using the same UTC time zone which does not shift. And I wouldn't be surprised if most spanning logistical organizations (planes, freight, etc) use some constant time zone for tracking and planning. If not they should.

Local, human, time

Partly why DST is so frustrating is at the human level, it's confusing and frustrating. We have a sudden shift. All of the drift our clock has with the sun is corrected at once, twice a year. Removing and gradual easing in and out of these shifts. If we normalized the global UTC time for all planning. Then we should slice up the map into proper local mean times. Each of these segments should more/less equate to proper solar times. Similarly, to leapseconds, adjusting themselves periodically throughout the year to correct for these drifts. I don't know about you, but my watch never stays accurate, and acts more as an estimation, so a bit of drift over a few months is something more easily corrected and keeps our own body clock even with what we see and feel outside.

That is likely the most tricky, and while probably reduces the shock of correcting our clocks to solar time and the stress that can cause on the body is probably over engineering things a bit to far in a connected world. With planes, trains, and automobiles it's not too uncommon to be changing time zones, and if these are now smaller and more frequent, and offset by 10-15minutes could lead to just a lot of confusion, even if plans are based around UTC time.

Just pick one and deal with it

This is my actual suggestion to the world. Analyze your countries time zone sliver. Average out the solar time consistency - optimizing your offset based on the average sunlight hours against the total sunlight hours per day. Whatever averages out across your longitudinal span wins. If it's too inconsistent maybe you need to slice up more? More incremental time zones (now we're getting to the previous suggestion). But winter will always suck. There is likely not much you can do for ensuring we get as much useful sunlight hours.

Some data

But we can just look at, at least in my timezone, if we stuck with either:

Sticking with DST

On the winter solstice, December 21st, 2022, we had 9 hours 18 minutes and 23 seconds of "day length". Solar noon was 6 minutes early at 11:54 (though in NY (where I am basing this from), the sun never really gets peak height anyway. So the sun rose at 7:14am and set at 4:33pm. Had we kept the DST the entire year this would mean sunrise would be at 8 and set at 5:30. Which isn't exactly great?

And moving backwards in time to November when we ended DST, we had a 7:30am sunrise which shifted down to 6:30. So as we approach solstice we crept more and more forward to 8pm sunrise, and closer and closer to 5:30 sunset. (At the switchover from DST -> Standard we had a 6:15pm sunset).

But as we move forwards, towards March, keeping DST, we return back to that 7am sunrise like we have now, and push closer and closer towards that 7pm sunset. Extending the day by nearly 3 hours over the course of 3 months (from solstice).

So reviewing this. What sucks about keeping DST is sunrise is BAD. Sunset stays fairly fine. If anything we have more sunlight during "awake" hours, for us lazy devs who sleep in until stand-up. But for anyone who actually wakes up early, it's darker for MUCH more of the morning in the winter months which probably sucks.

Sticking with Standard

So now we basically just reverse the numbers. At winter solstice, we have a 7:14am sunrise and 4:33pm sunset. This is our "worst day". So what do summer months look like?

So looking ahead to March, when we would normally enter DST, 6am / 6pm. That seems pretty fair, that's what it was the day prior, and as we move more and more into Spring time, sunrise moves early and early approaching 5am, and sunset pushes further towards 7pm. By May we have reached 4:54am sunrise and a 6:53pm sunset. And by summer solstice, June 21st, 2023, we have a wonderful 15 hours 8 minutes and 53 seconds long day. But sunrise is at 4:23am and sunset at 7:32pm. Which frankly isn't TOO bad. But does squander an hour of sunlight that could be pushed towards the evening.

That being said. On the summer solstice, in summer time, solar noon is ACTUALLY around noon, instead of 1pm like it is now. If we cared about that sort of thing.

But since after the 21st sunrise gets later and sunset early, that's the most extreme offset we have.

Conclusion

So what originally was some hot takes turned out to go in the direction of "let me just check by me". And I feel like DST would win out for me, as I would prefer to sneak some extra hours into the evening than morning. But if the government said "economically, having more sunlight in the morning helped logistics and farming", or if doctors said more sunlight closer to wake-up is better for you, I'd be fine with that. I really don't care. It doesn't take a mathematician to figure out we're only talking about +/- 1 hour difference. Just fucking pick one!

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