Spaced out: (continued)
This question actually has halachic issues at its core, and is nogeah lehalocha.
Did you ever notice that for a short period each year the zman tfila in the morning is getting later, but shkiah is also getting later? How is this possible? If the day is getting longer, it should do so at both the beginning and the end, and vice versa!
The answer is, because the earth’s position within its orbit has changed,a part of it will remain in its previous state (light or dark) later than it would have in its previous spot. Therefore if the change of the day’s length is less than the amount of additional daylight the new position would give it, the day will still end later, even if it is not longer.
(Rabbi Premock and anyone who has worked on a luach could probably explain this exponentially better)