3 A.M. : The American Sign Language (ASL) sign for "3 a.m. / 3A.M. / 3 in the morning / 3 ante meridiem"

There are two versions shown in the video below for the concept 3 A.M.

One version is produced by signing TIME-3 + MORNING.

The other version is produced by signing the number 3 incorporated into the sign for MORNING.