There are 200 sleeps (200 days) until May 11 (Tuesday, May 11, 2027).
There are 200 days until May 11 (Tuesday, May 11, 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 May 11. Sleeps are the same as days.
200 sleeps is 28 weeks and 4 sleeps.