December 21 - Unix Timestamps
The Unix timestamp for December 21 at midnight UTC, computed across recent and upcoming years. In 2026, December 21 falls on a Monday.
December 21 Across Years
| Date | Weekday | Unix Timestamp | ISO 8601 (UTC) |
|---|---|---|---|
| December 21, 2021 | Tuesday | 1640044800 | 2021-12-21T00:00:00Z |
| December 21, 2022 | Wednesday | 1671580800 | 2022-12-21T00:00:00Z |
| December 21, 2023 | Thursday | 1703116800 | 2023-12-21T00:00:00Z |
| December 21, 2024 | Saturday | 1734739200 | 2024-12-21T00:00:00Z |
| December 21, 2025 | Sunday | 1766275200 | 2025-12-21T00:00:00Z |
| December 21, 2026 | Monday | 1797811200 | 2026-12-21T00:00:00Z |
| December 21, 2027 | Tuesday | 1829347200 | 2027-12-21T00:00:00Z |
| December 21, 2028 | Thursday | 1860969600 | 2028-12-21T00:00:00Z |
| December 21, 2029 | Friday | 1892505600 | 2029-12-21T00:00:00Z |
| December 21, 2030 | Saturday | 1924041600 | 2030-12-21T00:00:00Z |
| December 21, 2031 | Sunday | 1955577600 | 2031-12-21T00:00:00Z |
All timestamps are at 00:00:00 UTC for that date.
Why might you need this?
Calendar-day timestamps are useful for cron schedules ("run every December 21 at midnight"), reminder systems, anniversary calculations, and reporting queries that bucket by date. The Unix value at midnight UTC is the canonical anchor - convert to your local zone if needed.