Today's Julian Date
See today's Julian date in both senses at once: the ordinal day-of-year stamp used on packaging and supplies, and the astronomical Julian Day Number. Both are read from your device's own calendar the moment the page opens, with the day of the year, the seven-digit ordinal form, the Julian Date at midnight UTC, the Modified Julian Date and the weekday listed underneath. Pick any other date to convert it, and the Today button brings today back.
Julian dateLoading today's date.
Two different numbers share one name. The ordinal date is the day of the year with a two-digit year in front, 001 to 365 or 366, which is what a packaging stamp, a ration date or a mainframe date field means by "Julian". The Julian Day Number is the astronomers' running count of days since noon UTC on 1 January 4713 BC, seven digits long today, with the Julian Date adding the fraction of the day from noon and the Modified Julian Date subtracting 2400000.5 to start the day at midnight. Both are shown for every date so nobody has to guess which one was meant. Dates run from year 1 to 9999, which is Julian Day Number 1721426 to 5373484. Leap years follow the Gregorian rule throughout, including for dates before 1582.
Common questions
- What is today's Julian date?
- The two large numbers at the top of the page: the ordinal stamp, YYDDD, first, and the Julian Day Number beside it, both for today as your device's calendar reads it. The stamp is the two-digit year followed by the day of the year, so on 2 September 2026 it is 26245. The Julian Day Number the same day is 2461286.
- Which of the two numbers is the Julian date on my packaging?
- The ordinal stamp, the five-digit one. Food, rations, medical supplies and military stock are dated by the day of the year, with a two-digit year in front; sometimes only the three digits of the day are printed. The Julian Day Number is the astronomical count and is seven digits long.
- Why does the page show the date from my calendar rather than UTC?
- Because today is the day on your wall. The UTC date is already tomorrow for the eastern half of the world every evening and still yesterday for the western half every morning, so a page that used it would stamp the wrong day for many visitors. The Julian Date at midnight UTC in the list below the numbers is where UTC comes in, and it is labelled as such.
- Does today's Julian date change at midnight?
- The ordinal stamp and the Julian Day Number both step forward by one at midnight on your calendar, since both count whole days. The astronomical Julian Date with its fraction turns over at noon UTC instead, which is why the list shows it for midnight UTC with a half at the end. The page reads today once when it opens, so after midnight press Today or reload it.
- How do I convert a different date, or a stamp back to a date?
- Pick any date in the Date field to see its two numbers. Switch the Mode to Ordinal to date and type a stamp such as 26245, or a bare day number such as 245 for this year, to read it back to a calendar date. Switch to JDN to date and type a Julian Day Number, or a Modified Julian Date, to do the same from the astronomical side.
Exact. The ordinal date counts days from 1 January, and the Julian Day Number uses the standard Gregorian algorithm; both are checked against known dates in the tests.