How “1 year ago” is calculated
Going back whole years keeps the same month and day and only changes the year. So 1 year before any date is the same date in the year 1 lower. The only exception is February 29: if the target year isn't a leap year, the date becomes February 28.
Example: 1 year before January 1, 2027
2027 − 1 = 2026, so the date is Thursday, January 1, 2026.
That span covers 0 leap years, for a total of 365 days.
That span covers 0 leap years, for a total of 365 days.
1 year before the 1st of each month in 2027
The weekday changes from year to year, so the same date 1 year ago may fall on a different day of the week:
| Date | 1 year earlier |
|---|---|
| January 1, 2027 | Thursday, January 1, 2026 |
| February 1, 2027 | Sunday, February 1, 2026 |
| March 1, 2027 | Sunday, March 1, 2026 |
| April 1, 2027 | Wednesday, April 1, 2026 |
| May 1, 2027 | Friday, May 1, 2026 |
| June 1, 2027 | Monday, June 1, 2026 |
| July 1, 2027 | Wednesday, July 1, 2026 |
| August 1, 2027 | Saturday, August 1, 2026 |
| September 1, 2027 | Tuesday, September 1, 2026 |
| October 1, 2027 | Thursday, October 1, 2026 |
| November 1, 2027 | Sunday, November 1, 2026 |
| December 1, 2027 | Tuesday, December 1, 2026 |
1 Year in other units
| Unit | 1 year is |
|---|---|
| Months | 12 |
| Weeks | about 52 |
| Days | 365 or 366 |
| Hours | about 8,760 |
To go back a specific number of days, months or weeks instead, use the Date Calculator. For the gap between two exact dates, try the Days Between Dates Calculator.