night out

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun literally Going away from one's usual residence for an entire night, and returning the next day.
• noun idiomatic Spending the evening away from one's usual residence. The phrase typically implies going to a restaurant, going to watch entertainment, or other types of urban nightlife, starting from about 6 p.m. to 8 p.m. and lasting until approximately 11:00 pm or later.