There are 58 sleeps (58 days) until December 20 (Sunday, December 20, 2026).
There are 58 days until December 20 (Sunday, December 20, 2026) — 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 December 20. Sleeps are the same as days.
58 sleeps is 8 weeks and 2 sleeps.