[_jstreet]

I agree with this. I've participated since 2016, but haven't yet completed all 25 puzzles, I usually burn out after about day 8-10 (partly due to the curve in difficulty).

I'm based in the UK, so the puzzles get unlocked at ~6AM which gives an hour or two before work if I wake up earlier than usual.

I think I'll still take part this year, but at a more relaxed pace.

[zeeZ]

Midnight EST (UTC-5) would be 5 am in the UK for the unlock time.

[johnday]

This is correct. I am a PhD student and I know several undergraduates who get up at 5am (or stay up until 5am) to get started on the AoC problems ASAP.

It's very unhealthy.

[estomagordo]

I'm in central Europe and so puzzles unlock at 6 here. I've often thought that this time is nearly ideal for me. But at the same time, had I lived in the UK, it would have been absolute hell to try and be competitive. So an hour can make a huge difference.

I have had days where I've just caved in to the lack of sleep and decided to sleep in the next day, sliding on leaderboards in the process.