[latterme]

Can we replace the time that we haven't sleep for the past years? I hope the answer is yes.

[Thunder Bow]

The answer is No and Yes. You can not replace time that is lost, but you mind and body can make up for it the next day.

[littletinyrock]

You can "pay back" your sleep debt over time. And doing so will definitely be to your benefit if you can:

Settle short-term debt. If you missed 10 hours of sleep over the course of a week, add three to four extra sleep hours on the weekend and an extra hour or two per night the following week until you have repaid the debt fully.

Address a long-term debt. Plan a vacation with a light schedule and few obligations. Then, turn off the alarm clock and just sleep every night until you awake naturally.

Avoid backsliding into a new debt cycle. Once you’ve determined how much sleep you really need, factor it into your daily schedule. Try to go to bed and get up at the same time every day — at the very least, on weekdays.