Late spring/early summer and late autumn/early winter. I think it's because of the extremes in how much light there is. Around summer solstice we get like 5 hours of absolute darkness and around winter solstice it's the opposite and either way makes it hard to sleep because I'm either awake because of the light or my sleep cycle is so off I go to bed at like 6 and wake up before midnight and then get really stressed about being the only one up.

Same Q