Two modes
Days-between and date add/subtract in one tool.
Date Calculator
日期计算器 — 日期间隔与加减日期
计算两个日期之间的天数，或在某日期上加减天、周、月、年，得出结果日期和星期。
总天数
0
间隔
0 周 0 天
What is the date calculator?
Count the days between two dates, or find what date falls a number of days, weeks, months, or years after (or before) a starting date. Handy for deadlines, '90 days from today', and D-day style counting.
How to use
- 1 Pick 'Days between' or 'Add / subtract' mode.
- 2 For days between, enter start and end dates; for add/subtract, enter a base date plus amount and unit.
- 3 Read the total days or the resulting date with its weekday.
Highlights
Shows weekday
Displays the weekday of the resulting date.
Months & years
Adds or subtracts months and years, not just days and weeks.
常见问题
What if the end date is before the start?+
The difference is shown as an absolute number of days, so the order doesn't change the result.
How are month-ends handled when adding months?+
It follows calendar rules. Adding one month to Jan 31 lands on the end of February (standard browser behavior).
Can it do '90 days from today'?+
Yes. In add/subtract mode, add 90 days to your base date to get the resulting date and weekday.
Related tools
Results use the Gregorian calendar. Leap years and month ends follow standard calendar rules.