"Daytime" refers to the period of the day when it is light outside, usually from the morning until the evening. It is the opposite of nighttime when it is dark. Full definition
The easiest way to spot the 2012 GT - R is by the horizontal row of LED daytime running lights. (automobilemag.com)
I have already seen many new cars with LED daytime running lights that do not require the light to turn off, to see the turn signal. (mechanics.stackexchange.com)
The upper section has LEDs for daytime running lights. (thesupercars.org)