DaylightQ

DaylightQ[] gives True if it is currently daylight from the user's location.

DaylightQ[datespec] gives True if it is daylight from the user's location on the specified datespec.

DaylightQ[locationspec] gives True if it is currently daylight from the specified locationspec.

DaylightQ[locationspec, datespec] gives True if it is daylight from the specified locationspec on the specified datespec.

Examples

Check if it's currently daylight:

DaylightQ[]

Please visit the official Wolfram Language Reference for more details.