There are 324 sleeps (324 days) until September 12 (Sunday, September 12, 2027).
There are 324 days until September 12 (Sunday, September 12, 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 September 12. Sleeps are the same as days.
324 sleeps is 46 weeks and 2 sleeps.