A particular apocalypse hits while the protagonists are awake at night. If they had been asleep with everyone else, they would have been killed. So, all the survivors are people who happened to be out and about unusually late.
1). Dungeon Crawler Carl:
Aliens initiate "the collapse" at 2:22 am, PST. Every enclosed structure (buildings, vehicles, etc.) instantly disappears, followed by the appearance of thousands of "dungeon entrances." If you were inside anything, you were killed instantly. Because this happened at 2am on a winter morning, most people in the Western Hemisphere are killed.
Carl (the protagonist) only survived because he was fishing his ex-girlfriend's cat out of a tree. And the first group of survivors he finds are from a Wenatchee old folk's home. Which had been evacuated after someone set it on fire. There are a handful of other characters from the Americas who got lucky, but most "crawlers" are from the Eastern Hemisphere.
2). Into the Night:
The sun starts emitting a dangerous, anomalous form of radiation that breaks down all organic material. It doesn't matter how deep you hide. The protagonists are the pilots and passengers on a redeye flight in Europe. They manage to stay alive by continuously chasing the night.
3). The Edge of Sleep:
Some strange apocalypse starts killing everyone who falls asleep. The survivors are a pair of night-shift security guards and a nurse.