Question 1

How age is counted

Accepted Answer

Age is the completed years, months, and days from your birth date to today — the same convention forms and officials use. Months differ in length, so the calculator borrows the correct number of days from the previous month rather than assuming 30.

Question 2

Days between two dates

Accepted Answer

The date-difference tool counts whole days from the earlier date to the later one, then expresses the same span in weeks and in years-months-days. Swap the dates and the answer is the same magnitude — order doesn’t change the gap.

Question 3

Where it’s handy

Accepted Answer

Visa and pension age checks, working out a baby’s age in months, counting down to an event, tracking how long since a milestone, or measuring a project’s run length in days for billing.

Question 4

Common mistakes

Accepted Answer

Counting both endpoints (off-by-one); assuming every month is 30 days; and ignoring leap years — the calculator handles all three using real calendar dates.

年龄计算器 — 精确年龄与日期间隔

年龄如何计算

两个日期之间的天数

什么时候好用

常见错误

它不做的事