around the equinoxes the change in sunset time becomes so obvious week to week (when i’m doing regular activities, e.g. driving home at a certain time – i see a lot of sunsets, and very few sunrises) – i wanted to see the actual quantification of it – been thinking about a graph like this for a while, but never got around to making it. i live around 40 degrees north, this time of year the sunset is almost 10 minutes earlier each week!
tools: the ‘sunset equation’, and a python notebook
(edit, obviously by NH latitude i meant “northern hemisphere” not “new hampshire” but now i see it looks kinda weird and it’s bugging me.. )
Kaister0000 on
Thanks! I was wondering about taking the derivation of sunset times as well. Like it makes obvious sense that the at equinox you would see the fastest change in sunset times. And at solstice would be the least amount of change. But always wondered what that rate of change looked like between.
![Week-to-week change in sunset time (by date and NH latitude) [OC]](https://www.byteseu.com/wp-content/uploads/2025/10/choainxowwsf1-1024x766.png "Week-to-week change in sunset time (by date and NH latitude) [OC]")
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around the equinoxes the change in sunset time becomes so obvious week to week (when i’m doing regular activities, e.g. driving home at a certain time – i see a lot of sunsets, and very few sunrises) – i wanted to see the actual quantification of it – been thinking about a graph like this for a while, but never got around to making it. i live around 40 degrees north, this time of year the sunset is almost 10 minutes earlier each week!
tools: the ‘sunset equation’, and a python notebook
(edit, obviously by NH latitude i meant “northern hemisphere” not “new hampshire” but now i see it looks kinda weird and it’s bugging me.. )
Thanks! I was wondering about taking the derivation of sunset times as well. Like it makes obvious sense that the at equinox you would see the fastest change in sunset times. And at solstice would be the least amount of change. But always wondered what that rate of change looked like between.
Ah, it’s the slope of the sunset times graph.
That’s interesting, yes.