Enter a date and the weekday and distance from today appear here.
Enter any past or future date to get its weekday, how many days from today it is, the day of the year, the ISO week number, the number of days in that month and whether it is a leap year. You can also count N days from today.
FAQ
Does it know public holidays?
No. Japanese public holidays move with legislation, substitute days and the Happy Monday system, and single-year exceptions occur, as in the Tokyo Olympics year. A baked-in list would quietly become wrong. When holidays matter, take the current year's list published by the Cabinet Office.
How far back and forward does it go?
Broadly across the Gregorian calendar. Note that Japan moved to the solar calendar in 1873, so dates before that do not correspond to the lunisolar dates actually in use at the time. When researching a historical date, establish which calendar the source is written in first.
Can I pass the result to someone?
"Copy result" takes the weekday, date, day of the year and week number together, formatted to paste straight into an email or a chat.
Is the date I enter stored?
No, and nothing is sent. The calculation happens entirely in the page.