There are 204 sleeps (204 days) until May 15 (Saturday, May 15, 2027).
There are 204 days until May 15 (Saturday, May 15, 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 15. Sleeps are the same as days.
204 sleeps is 29 weeks and 1 sleep.