I need a word (ideally) or phrase that means "daytime" that can be used in a sentence "the event happened at dawn/dusk/night/day"
"The event happened at day", and "The event happened at daytime" don't seem to really sound right.
The key thing here is fitting into a sentence that has the word 'at' in it, because it is going into construction of a sentence on a web site that has to cover these possibilities.
A typical example might be "The battle occurred at night in the rain", or "The battle occurred at day in the mist". The latter doesn't sound right.