every night; night after night
Describes something that happens on consecutive nights, often in news reports about events, work, or disturbances.
連夜の残業で疲れがたまっている。
I'm exhausted from working overtime night after night.
その地域では連夜、花火大会が開かれた。
In that area, a fireworks festival was held every night.
day and night; every day and every night; around the clock
Compound of 連 (ren, 'in succession') and 夜 (ya, 'night'). The reading is on'yomi, and the word follows standard Sino-Japanese word formation.