There are 351 sleeps (351 days) until October 10 (Sunday, October 10, 2027).
There are 351 days until October 10 (Sunday, October 10, 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 October 10. Sleeps are the same as days.
351 sleeps is 50 weeks and 1 sleep.