This happens a lot if the uk too, though times vary depending in sunset/sunrise throughout the year.
Sometimes the safety of the rescue teams has to be taken into account too, as well as the available resources at any one time.
Often official searches may finish at a certain time, but unofficial ones continue,
I've know that situation once before near home, a vulnerable teen went missing. The official search stopped overnight, for various reasons, but unofficial volunteers kept looking, albeit to no avail overnight. Teen was found elsewhere later the next day, by the official search teams.