ISO WEEK
51
2025
December 15 – December 21, 2025
Week 51 of 52
98% through 2025
Days in Week 51
MonDecember 15
🌘 Waning Crescent
TueDecember 16
🌘 Waning Crescent
WedDecember 17
🌘 Waning Crescent
ThuDecember 18
🌑 New Moon
FriDecember 19
🌑 New Moon
SatDecember 20
🌑 New Moon
SunDecember 21
🌑 New Moon
Moon Phases This Week
- 🌘 Waning Crescent — Monday, December 15
- 🌘 Waning Crescent — Tuesday, December 16
- 🌘 Waning Crescent — Wednesday, December 17
- 🌑 New Moon — Thursday, December 18
- 🌑 New Moon — Friday, December 19
- 🌑 New Moon — Saturday, December 20
- 🌑 New Moon — Sunday, December 21
FAQs
When does Week 51 2025 start and end?
Week 51 of 2025 starts on December 15 (Monday) and ends on December 21, 2025 (Sunday).
What month is Week 51 in?
Week 51 of 2025 is primarily in December.
How many weeks are in 2025?
2025 has 52 ISO weeks. Most years have 52 weeks.
