Tools / Date

Age & Date Calculator

Calculate age with Gregorian and Japanese era birth dates, compare two dates, or add and subtract a period from a date.

Calculate age

Birth-date input

Gregorian Japanese era

Birth date

Paste a date with the year first: 1990/1/23, 1990-01-23, 19900123, or 1990年1月23日. Full-width digits are supported.

Choose from a calendar

Select birth date

Reference date

Dates stay in your browser and are not transmitted. Japanese era dates are checked against the exact start and end date of each era before conversion. The Japanese zodiac is based on the Gregorian birth year. Birthstones follow the 2021 list from the National Association of Jewellers in Japan. Birth-flower lists are not standardised, so one representative flower for each month is shown. For a 29 February birth date, 28 February is used as the corresponding date in non-leap years. Check the relevant authority when a legal or administrative age is required.

Date & period calculations

Find the duration between two dates, or add and subtract years, months, and days.

Duration between two dates

Calculate the calendar period and total elapsed days from a start date to an end date.

Add or subtract a period

Years, months, and days are applied in that order. Enter negative values to subtract.

If the corresponding day does not exist after adding a month or year, the last day of that month is used. For example, one month after 31 January is the final day of February.