There are 150 sleeps (150 days) until March 22 (Monday, March 22, 2027).
There are 150 days until March 22 (Monday, March 22, 2027) — one sleep per night.
One sleep per night between now and the big day — tonight is the first sleep, and the morning after the last sleep is March 22. Sleeps are the same as days.
150 sleeps is 21 weeks and 3 sleeps.