야근각

That sinking realization that you're not going home on time today. From 야근 (overtime/late-night work) + 각 (signs of, slang suffix). When the workload, the meeting, or the boss makes it painfully clear that tonight is going to be a long one.

야근 = overtime, late-night work

각 = signs of, potential (slang suffix, from '각'도 — angle)

See also: 차애각, 망각, 후회각, 야근각

Opposite: 칼퇴각