People who work night shifts often have their day-and-night reversed.
Tips
culture
晨昏定省, 'tend to parents at dawn and dusk', was a Confucian filial duty: a child should arrange a parent's bedding at night and check on them in the morning. The phrase 晨昏 carries that classical resonance even in modern use.
register
Literary tone. In casual speech, 早晚 covers the same ground. 晨昏 shows up in poetry, idioms (晨昏颠倒), and reflective writing.
