시차가 · 시차를
time difference; jet lag
Example
한국과 미국은 시차가 커서 전화하기 힘들어요.
There's a big time difference between Korea and the US, so it's hard to call.
Word parts
시 time+차 difference
Literally 'time difference'.
Good to know
For jet lag, say 시차 적응이 안 돼요, literally 'I can't adjust to the time difference.'