2021 Unix Timestamps
Unix timestamps for the start of each month in 2021. January 1, 2021 00:00:00 UTC = 1609459200.
January 2021 (local)Jan 1, 2021, 12:00:00 AM UTC
1,609,459,200s
February 2021 (local)Feb 1, 2021, 12:00:00 AM UTC
1,612,137,600s
March 2021 (local)Mar 1, 2021, 12:00:00 AM UTC
1,614,556,800s
April 2021 (local)Apr 1, 2021, 12:00:00 AM UTC
1,617,235,200s
May 2021 (local)May 1, 2021, 12:00:00 AM UTC
1,619,827,200s
June 2021 (local)Jun 1, 2021, 12:00:00 AM UTC
1,622,505,600s
July 2021 (local)Jul 1, 2021, 12:00:00 AM UTC
1,625,097,600s
August 2021 (local)Aug 1, 2021, 12:00:00 AM UTC
1,627,776,000s
September 2021 (local)Sep 1, 2021, 12:00:00 AM UTC
1,630,454,400s
October 2021 (local)Oct 1, 2021, 12:00:00 AM UTC
1,633,046,400s
November 2021 (local)Nov 1, 2021, 12:00:00 AM UTC
1,635,724,800s
December 2021 (local)Dec 1, 2021, 12:00:00 AM UTC
1,638,316,800s
Start of 2022 (year-end boundary, local)Jan 1, 2022, 12:00:00 AM UTC
1,640,995,200s
2021 year boundaries
Start of 2021: 1609459200 (January 1, 2021 00:00:00 UTC). Start of 2022 (exclusive year-end boundary): 1640995200. 2021 is a common year with 365 days.
Quarter and half-year boundaries
Quarter and half-year boundaries for 2021 in UTC. Use these for quarter-over-quarter reports, fiscal queries, and BI dashboards. All values are seconds since the Unix epoch.
- Q1 start (Jan 1): 2021-01-01 00:00:00 UTC = 1609459200
- Q2 start (Apr 1): 2021-04-01 00:00:00 UTC = 1617235200
- H1 end / Q3 start (Jul 1): 2021-07-01 00:00:00 UTC = 1625097600
- Q4 start (Oct 1): 2021-10-01 00:00:00 UTC = 1633046400
- Year end (Dec 31 23:59:59): 2021-12-31 23:59:59 UTC = 1640995199
- Next year start (Jan 1, 2022): 1640995200
Code: get the start and end of 2021 as epoch
One-liners for computing year boundary timestamps in popular languages. All return UTC seconds; multiply by 1000 for milliseconds.
- JavaScript: Math.floor(Date.UTC(2021, 0, 1) / 1000) // → 1609459200
- Python: int(datetime(2021, 1, 1, tzinfo=timezone.utc).timestamp()) // → 1609459200
- Go: time.Date(2021, 1, 1, 0, 0, 0, 0, time.UTC).Unix() // → 1609459200
- Java: ZonedDateTime.of(2021, 1, 1, 0, 0, 0, 0, ZoneOffset.UTC).toEpochSecond()
- PostgreSQL: SELECT EXTRACT(EPOCH FROM '2021-01-01 00:00:00 UTC'::timestamptz)::bigint
- SQL Server: DATEDIFF_BIG(SECOND, '1970-01-01', '2021-01-01')
- Shell (Linux): date -u -d '2021-01-01 00:00:00 UTC' +%s
Notable dates in 2021
Common reference moments in 2021 in UTC seconds. Useful for testing range queries, charting historical events, and verifying DST transitions.
- January 1, 2021 00:00 UTC (year start): 1609459200
- US DST starts — second Sunday of March 07:00 UTC: 1616310000 (02:00 EST → 03:00 EDT)
- US DST ends — first Sunday of November 06:00 UTC: 1636264800 (02:00 EDT → 01:00 EST)
- December 31, 2021 23:59:59 UTC (year end, inclusive): 1640995199
- Days in 2021: 365 (common year — no Feb 29)
- ISO week 1 begins on the Monday of the week containing Jan 4, 2021