system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: A full day is approx 23 hours 56 minutes rather than 24 hours. This is why we have leap years. But why doesn’t that gradual daily 4 minute shift not cause our daylight hours to shift?

A 4 minute time shift daily would be a one hour shift in 15 days. So how is it that daylight is basically the same day to day outside of a minute adjustment. I would think that this discrepancy would eventually cause it to be dark at 12 noon and light. Obviously this is not the case, so please enlighten me!
gpt
Firstly this have nothing to do with leap years. What you are citing is not the length of a full day but rather the length of a full rotation of the Earth. You are right that a 4 minute daily time shift would be an hour in 15 days, 2 hours in a month and 24 hours in a year. But by that time the Earth have rotated around the Sun once and you have gained another day. This makes up for the missing 4 minutes a day.

If you were to observe the sky and look at a distant star then it would appear in the same location approximately every 23 hour and 56 minutes. However because the Earth is constantly moving around the Sun it shows up 4 minute late every day compared to all the other stars. And thus you have 24 hours in a day even though the Earth rotates 4 minutes faster.