Nighttime (noun)

The period of darkness during each 24-hour day.

Origin:

From night + time, the period of darkness during each 24-hour day.

Examples:

1. The city is particularly beautiful at nighttime, when the lights are on.
2. Many animals are active during nighttime hours.
3. The nighttime temperature was much cooler than during the day.
4. She always felt more alert and productive during nighttime hours.
5. The store was closed, it was nighttime.