日期计算器
从 1 月 1 日到现在过了多少天?把 1 月 1 日设为开始日期、今天设为结束日期即可算出。本计算器可计算任意两个日期之间的天数,或在某个日期上加减天数,并考虑闰年。
结果
输入数值并点击“计算”查看结果。
公式
Dates are counted as whole calendar days, including leap days (the end date is not counted twice).
如何使用此计算器
- Choose the mode and pick the dates.
- The difference counts from the start date up to (not including) the end date.
例题
Days from 1 January to 25 December 2026
25 December is day 359 of 2026, and 1 January is day 1.
So there are 358 days between them: 51 weeks and 1 day.
Easy: days since 1 January, counted on 1 June 2026
January 31 + February 28 + March 31 + April 30 + May 31 = 151 days.
So on 1 June 2026 it had been 151 days since January 1.
Medium: days since January 1, 2025
From 1 January 2025 to 1 January 2026 is 365 days (2025 isn’t a leap year).
From 1 January to 2 November 2026 is 305 more days, so the total is 670 days.
Hard: across a leap day
2024 is a leap year, so February has 29 days.
January 31 + February 29 = 60 days from 1 January to 1 March.
常见错误
- Counting both the start and end dates: from 1 January to 2 January is 1 day.
- Forgetting leap years: years divisible by 4 have 29 February, except century years not divisible by 400.
- Using 30-day months: real months have 28 to 31 days, so always count the actual calendar.
常见问题
How many days ago was January 1?
Put 1 January of this year as the start date and today as the end date. On 2 November 2026, for example, January 1 was 305 days ago.
Are leap years handled?
Yes — every date is converted to an exact calendar day count.
Does it count the end date?
No. From Monday to Tuesday is 1 day. Add 1 if you want to include both ends.