And the most dangerous time for a carrier was when they are in the middle of an UnRep. Having the benefit of darkness, especially in the Med, is a plus.
And no, I was not part of deck division. For one year of my enlistment I was in charge of the cargo ordinance for the USS Savannah AOR-4. In 3 cruises we never once did an UnRep for a carrier during daylight hours. Perhaps that changed later, but it was that way when I was in.
Part of it was done for security, since any air attack at night would have to use active radar. And part of it was done because when the carrier is being serviced, it was being done solo. During the day the supply ship would often have a ship on each side and vertical UnReps being done for a third ship.
The UnRep also was done when the flight ops were at a minimum, to avoid any chance of igniting any spilled fuel (marine diesel or JP5)