Find today’s Julian date, convert any calendar date to a Julian date code, or decode a code back to a date. It handles every common format: the 5-digit YYDDD and 7-digit YYYYDDD codes used in manufacturing, the military and logistics, the 6-digit CYYDDD dates in JD Edwards and IBM systems, the 4-digit lot codes printed on food cans, and the astronomical Julian Day used in science. Below the converters are a printable Julian date calendar and a converter between the old Julian calendar and today’s Gregorian calendar.
Today’s Julian date
Convert a date to a Julian date
Convert a Julian date to a calendar date
Decode a list of Julian dates
Paste one code per line, for example from a stock sheet or a batch of lot codes. Each line is read with the format chosen above.
Julian calendar ↔ Gregorian calendar
For historical dates and Orthodox church dates: the old Julian calendar, which most of Europe used before 1582 and Russia until 1918, now runs 13 days behind the Gregorian calendar.
Julian date calendar (day of the year)
What “Julian date” means
The same name is used for three different things, which is why Julian dates confuse people:
- An ordinal date code (the most common use): the year followed by the day of the year, counted from 1 to 365, or 366 in a leap year. November 1, 2026 is day 305, so it is written 26305 or 2026305. This is what "Julian date" means on packaging, in warehouses, in military paperwork and in many business systems. Strictly speaking it is an ordinal date, not a Julian date, but the name has stuck.
- The astronomical Julian Day (JD): a running count of days since noon Universal Time on January 1, 4713 BC. Astronomers, satellite operators and software use it because it turns any date into a single number. Each JD day starts at noon UTC, so midnight UTC is always a number ending in .5.
- The Julian calendar: the calendar Julius Caesar introduced, in use from 45 BC. Most countries replaced it with the Gregorian calendar between 1582 and the early 20th century, and some Orthodox churches still use it for religious holidays.
Julian date formats at a glance
| Format | Example for November 1, 2026 | Where you see it |
|---|---|---|
| YYDDD | 26305 | Manufacturing, shipping, military, airline and logistics systems |
| YYYYDDD | 2026305 | Databases and systems that avoid two-digit years (also written 2026-305 in the ISO 8601 standard) |
| CYYDDD | 126305 | JD Edwards EnterpriseOne and IBM systems; the first digit is the century, 0 for the 1900s and 1 for the 2000s |
| YDDD | 6305 | Lot and batch codes on cans and packaged food, where the last digit of the year is enough |
| Julian Day (JD) | 2,461,346.0 at noon UTC | Astronomy, space and scientific software |
| Modified Julian Day (MJD) | 61,345 at midnight UTC | Science and engineering; MJD = JD minus 2,400,000.5, so it starts at midnight |
How to read a Julian date code
Split the code into the year part and the last three digits. The last three digits are always the day of the year. In 26060, 26 is the year 2026 and 060 is day 60, which is March 1. In a leap year the same code means one day earlier from March onward: 24060 is February 29, 2024. That is why the calendar above changes when you pick a leap year.
Lot codes with a one-digit year need a little judgment, because the digit repeats every ten years. A can stamped 6120 was made on day 120 of a year ending in 6: in practice that is 2026 or 2016, and the converter shows the most recent date that is not in the future. Some manufacturers add letters or a plant number around the date, so if a code does not fit, look for a run of four or five digits inside it. If you are checking whether food is safe to eat, the "best before" or "use by" date on the package matters more than the production code.
Converting Julian dates in Excel or Google Sheets
To turn a 5-digit YYDDD code in cell A1 into a date, use =DATE(2000+LEFT(A1,2),1,RIGHT(A1,3)) and format the cell as a date. Excel counts the extra days forward from January, so day 305 lands on November 1. For a 7-digit YYYYDDD code use =DATE(LEFT(A1,4),1,RIGHT(A1,3)). To go the other way, from a date in A1 to YYDDD, use =TEXT(A1,"yy")&TEXT(A1-DATE(YEAR(A1),1,0),"000"). If codes from the 2000s have lost their leading zero in the spreadsheet (5001 instead of 05001), use TEXT(A1,"00000") in place of A1 in the first formula. The batch decoder above does the same for a pasted list without formulas.
Julian calendar vs Gregorian calendar
The Julian calendar adds a leap day every four years without exception, which makes its year about 11 minutes too long. By the 1500s the calendar had drifted 10 days from the seasons, so Pope Gregory XIII introduced the Gregorian calendar in October 1582: Thursday, October 4 was followed by Friday, October 15. Britain and its colonies switched in 1752, when Wednesday, September 2 was followed by Thursday, September 14. Russia changed in 1918 and Greece in 1923.
Today the gap is 13 days. That is why Orthodox Christmas, December 25 in the Julian calendar, falls on January 7 in the Gregorian calendar. The gap stays 13 days until 2100, when the Julian calendar has a February 29 that the Gregorian calendar skips: from Gregorian March 14, 2100 the difference becomes 14 days.
Frequently asked questions
What is today’s Julian date?
It is shown in every format at the top of this page and updates automatically, based on the date on your device. The ordinal codes change at your local midnight, while the astronomical Julian Day changes at noon UTC.
Is a Julian date the same as the day of the year?
In everyday business use, yes: the last three digits of a YYDDD or YYYYDDD code are the day of the year. In astronomy, no: the Julian Day is a continuous count of days since 4713 BC and has nothing to do with the day of the year.
What is the Julian date for January 1?
January 1 is always day 001, so January 1, 2027 is 27001 in YYDDD format, 2027001 in YYYYDDD and 127001 in JD Edwards CYYDDD format. December 31 is day 365, or day 366 in a leap year such as 2028.
Why does the astronomical Julian Day start at noon?
The system was set up for astronomers, who observe at night. Starting the day at noon meant a whole night of observations had the same day number.
How accurate is this converter?
Conversions use the standard integer formulas for the Gregorian and Julian calendars and were checked against reference values such as J2000 (JD 2,451,545.0 = January 1, 2000 at noon UTC), the start of MJD (November 17, 1858) and the 1582 and 1752 calendar changes. Dates before October 15, 1582 are shown in both calendars, because the Gregorian calendar did not exist yet.
Related: today’s day of the year, days left in the year, count days from today and how leap years work.
Definitions of the Julian Day and MJD follow the Hong Kong Observatory time glossary. Last checked: November 1, 2026.