Question

(to) burn the midnight oil The bank needs our financial statements completed by 9 a.m. tomorrow. We're going to need to burn the midnight oil tonight to finish on time.origin: This expression dates back to the days before electricity, when oil lamps were used for lighting. People went to sleep earlier back then, so if you were still burning the oil at midnight, you were staying up late.

Accepted Answer

to stay up late working or studying

Idiom	(to) burn the midnight oil
Meaning	to stay up late working or studying
Example	The bank needs our financial statements completed by 9 a.m. tomorrow. We're going to need to burn the midnight oil tonight to finish on time. origin: This expression dates back to the days before electricity, when oil lamps were used for lighting. People went to sleep earlier back then, so if you were still burning the oil at midnight, you were staying up late.

Oil Burn Midnight Back Stay Late Working Studying