This story appeared in Today, Explained, a daily newsletter that helps you understand the most compelling news and stories of the day. Subscribe here. Hi readers, happy Friday! We have a big weekend coming up: Halloween, the New York Marathon — and the end of daylight saving time. At 2 am on Sunday, our clocks will fall back one hour, returning us to standard time for the next four and a half months or so.  Depending on who you ask, it’s either the welcome return of before-work sunshine, or the start of a dreary slog through 4:30 pm sunsets. (The good news, though, is that however y...