Last night, Israel switched off of Summer Clock (aka Daylight Saving Time) onto Winter Clock. This means that until the US switches (which is now in November, because Congress decided that it was a good idea to have an extra week of waking up in the dark), the time difference between the US and Israel will be one hour less. I.e., we'll now be 6 hours ahead of EDT and 7 hours ahead of CDT.
Until the passage of the Israeli Daylight Saving Law in 2005, there was no fixed algorithm for the beginning and end of DST, and so the Knesset would fight over it every year as if summer had never happened before and would never happen again. Now, it is guaranteed that Winter Clock will begin before Yom Kippur, so that the fast is shorter.
SHF and I used to debate this endlessly. I would argue that the fast is 25 hours no matter what, so if the fast ends an hour earlier, then it also starts an hour earlier, so you don't gain anything. SHF would say that it still makes a difference, because how hungry you feel depends on how much time has elapsed since you woke up. I would respond that the time from when you wake up until the end of the fast isn't going to change, if you're now waking up an hour earlier because services are starting earlier due to the clock change. This assumes that you care about getting there on time. If you don't, then sleep as late as you want, and the clock change doesn't matter. One might respond that the time you'll naturally get up (assuming you're not getting up earlier due to earlier service times) is the time that you're used to getting up, and so the time from when you get up until the end of the fast will indeed be shorter. I would respond that if you just switched off Summer Clock a few days ago, then your biological clock hasn't adjusted yet, so you're not going to instantly start waking up at a different time (unless you want to, which again is a choice you can make without changing your clock). In the end, perhaps the only convincing argument for how the clock change makes the fast easier is psychological sleight of hand: you think it's only 6:00 instead of 7:00.
The one thing that this clock change does accomplish is make Tzom Gedaliah effectively shorter. Yes, the time from sunrise to sunset is unchanged, but if you're not getting up before sunrise to eat, then the time from when you last ate (before going to bed) until the end of the fast is going to be shorter.