Idiom: Burn the candle at both ends
Meaning: To give extreme effort with little time for rest for a number of days or weeks. Usually the person is working hard all day and night, going to sleep very late and getting up early.
Before we had electricity, people would burn a candle at night in order to work, you would not burn the candle during the day because it would be wasteful and expensive. But if you’re working very hard all day and night, then in a way you’re having to waste valuable resources to get your task done.
Mary looks so tired every time i see her, that poor woman is really burning the candle at both ends trying to pay her bills.
John, congrats on completing this project on time and on budget. I know you had to sacrifice yourself by burning the candle at both ends for a few months, so I’m giving you a week off so you can recuperate. Well done!