daybreak
n. uncountable B2 Upper Intermediate US //ˈdeɪˌbɹeɪk// UK //dˈeɪbɹeɪk// day·break
n. the time in the early morning when light first appears in the sky. It is the very start of the day before the sun fully rises.
n. the first appearance of light in the morning sky; the beginning of daylight. Often used in literary or descriptive contexts to mark the transition from night to morning.
The birds began to sing at daybreak.
The hikers woke up before daybreak to reach the mountain summit by sunrise.
As the grey shadows of night retreated at daybreak, the valley below was slowly revealed through a thin layer of morning mist.
From day + break.
Usage
Often used with the preposition 'at' to indicate a specific time.