Looking on the internet deeply has found these results:

daytime is the most popular phrase on the web.

day time 122,200,000 results on the web	daytime 182,300,000 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
outline, front side, rear Limited to day time journeys (for example: End End marker lamps Limited to day time journeys (for example: one hour after sunrise and one hour before sunset) side, stop, day time running, side	Narcolepsy is a sleep disorder that causes excessive daytime sleepiness. It's his first daytime disposal. Algorithm 5 is used both for night Now the safety... Exclusive daytime. Sleep apnea can cause excessive daytime sleepiness. time ancillary system operations and daytime processing. Studies all around the world have shown that children benefit from being supported and taught in a daycare facility or by a daytime carer. My wife daytime drinks on vacation.

day time

122,200,000 results on the web

daytime

182,300,000 results on the web

More popular!

outline, front
side, rear
Limited to day time journeys (for example:
End
End
marker lamps
Limited to day time journeys (for example: one hour after sunrise and one hour before sunset)
side, stop, day time running, side

Narcolepsy is a sleep disorder that causes excessive daytime sleepiness.
It's his first daytime disposal.
Algorithm 5 is used both for night
Now the safety... Exclusive daytime.
Sleep apnea can cause excessive daytime sleepiness.
time ancillary system operations and daytime processing.
Studies all around the world have shown that children benefit from being supported and taught in a daycare facility or by a daytime carer.
My wife daytime drinks on vacation.