Your Source for 'Ff'lo

It's darkest when the sun is at least 15 degrees below the horizon. Which is more or less an hour and a half after sunset until an hour and a half before sunrise, depending on latitude and time of year. Of course during that time, light pollution varies, and is likely to decrease as the night goes on, and traffic decreases and some sources shut down.

But it reminds me of a calculus thing, really, That the derivative is zero at a minimum, and the more common sense that after a minimum, it's inevitable that stuff increases. Which, I suppose is the metaphor they want. Of course some functions are monotonically downward, and the expression denies that.

If shit gets better, it gets better after it gets its worst doesn't sound as perky and positive.

Kind of like "Life will never give you more than you can handle," which should really be "Life will never give you more than you can handle, except once, because you *will* die."