There are 149 sleeps (149 days) until March 21 (Sunday, March 21, 2027).
There are 149 days until March 21 (Sunday, March 21, 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 21. Sleeps are the same as days.
149 sleeps is 21 weeks and 2 sleeps.