Today is Saturday, June 6, 2026. The Julian date today is 26157 in the common YYDDD format used on factory codes, mainframe systems, and food packaging. This is day 157 of 2026.
In other formats, today’s Julian date is 2026157 (YYYYDDD with 4-digit year), 2461197.5 (astronomical Julian Date), and 61197.0 (Modified Julian Date or MJD). Use the Julian date converter below to convert any other date or to convert a Julian date back to a calendar date.
Julian Date Today and Online Converter
Today’s Julian date
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Last two digits of the year followed by the day of the year. This is what most people mean when they say “Julian date” — used on factory date codes, mainframe systems, and food packaging.
Same as YYDDD but with a 4-digit year. Avoids century ambiguity.
The day number on its own (1–366). Common in agriculture and scientific data logging.
Days since noon UTC, January 1, 4713 BC. The “true” astronomical Julian date — used by NASA and observatories.
JD minus 2,400,000.5. Counts days from midnight Nov 17, 1858 — used in satellite tracking and geodesy.
Convert a calendar date
Convert a Julian date back to a calendar date
Quick reference: first of each month
| Date | DOY | YYDDD | YYYYDDD |
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Bulk convert
Paste calendar dates (one per line, format YYYY-MM-DD). Tab-separated output pastes into Excel or Google Sheets cleanly.
All conversions use UTC. Two-digit years from 00 to 49 are interpreted as 21st century (e.g., 26 = 2026), and 50 to 99 as 20th century (e.g., 99 = 1999) — the convention used by most mainframe systems.
Free printable Julian Calendar 2026 in monthly or yearly format that you can download instantly, plus a Julian date converter that handles every format — the YYDDD code used on factory date stamps and mainframe systems, the astronomical Julian Date used by NASA, the Modified Julian Date used in satellite tracking, and more. Convert any date in either direction, or process a whole list at once.
The Julian Calendar
What is the Julian date?
The term "Julian date" actually refers to several different things depending on the field. Here's what each one means and where you'll see it.
Ordinal date (YYDDD) — the "common" Julian date
This is what most people mean when they say "Julian date" today. It's a five-digit code: the last two digits of the year followed by the day of the year (001–366). For example, April 29, 2026 is 26119, because it's day 119 of 2026.
You'll find this format on:
- Factory date codes and product lot numbers
- Food packaging and expiration codes
- Mainframe systems, especially in finance, insurance, and logistics
- Shipping and inventory tracking
A four-digit-year variant, YYYYDDD (for example, 2026119), is sometimes used to avoid century ambiguity in long-term records.
Technically, this format is called an ordinal date, not a Julian date. But "Julian date" is what mainframe and operations teams have called it for decades, and the term stuck. If someone hands you a five-digit code and calls it a Julian date, this is almost certainly what they mean.
Astronomical Julian Date (JD)
This is the original, formal Julian Date used by astronomers. It's a continuous count of days — with a fractional part for the time of day — since noon Universal Time on January 1, 4713 BC, the start of the Julian Period defined by the scholar Joseph Scaliger in 1583.
Today's astronomical JD is around 2,461,159. NASA, observatories, and orbital mechanics calculations all use this number, because it lets you compute the time between any two events without worrying about months, years, or calendar reforms.
Modified Julian Date (MJD)
The astronomical JD is a big number. The Modified Julian Date, introduced by the Smithsonian Astrophysical Observatory in 1957 to track the Sputnik satellite in 18 bits of memory, simplifies it:
MJD = JD − 2,400,000.5
The half-day shift moves the start of the day to midnight rather than noon, which lines up better with how computers store time. MJD is widely used in satellite tracking, geodesy, GPS, and most scientific applications where a smaller, midnight-aligned day count is more practical.
Other variants you may encounter
Reduced Julian Date (RJD) — JD minus 2,400,000. Similar to MJD but without the half-day shift.
Truncated Julian Day (TJD) — JD minus 2,440,000.5, used by NASA in some mission contexts.
These are rare in everyday use. The converter at the top of this page handles the three most common formats: YYDDD, astronomical JD, and Modified Julian Date.cific field or application.
Printable Julian Calendar 2026-2032
Here is a free printable Julian date calendar in a yearly and monthly format. You can download it as an image or a PDF file. See the top of this page to see today's date with our Julian date converter.
The Gregorian Calendar
What is the Gregorian calendar?
Pope Gregory X111 invented the Gregorian calendar in 1582. This new style calendar, which is used up to date, upgrades the Julian calendar. It reduces the number of days in a year from 365.25 to 365.2425 days. To ensure that the calendar is in sync with the equinoxes, Pope Gregory shortened the Julian calendar year by 0.0075 days. The date was altered in October 1582; the day after Thursday 4th October 1582 was Friday 15th October 1582.
In the Gregorian calendar, a leap year is any year divisible by four, while those divisible by 100 and 4 aren’t leap years if not divisible by 400. Similarly, centurial years divisible by 400 are leap years.
Within a year after the invention of the Gregorian calendar, the Roman Catholic German states, Italian states, Spain, and Portugal started to use this calendar. Other states eventually came on board, for instance, Great Britain in 1752, Protestant German countries in 1699, Sweden in 1753, China in 1912, Greece in 1923, and Japan in 1873, among other countries.
The solar year differs from the Gregorian calendar by 26 seconds. Eventually, the solar year will be a full day behind the Gregorian calendar in the year 4909.
The initial goal of introducing the Gregorian calendar was to change the Easter date, which was not in sync with the seasons in the solar year. When still new, some protestants rejected the Gregorian calendar, claiming it was a Catholic plot to silence them.
However, in 1700, German Protestants switched over, followed by England Protestants in 1752. The orthodox countries continued to use the Julian calendar for years before adopting the new style calendar. Their national churches have never embraced the changes to date.
Julian vs Gregorian Calendar
What is the difference between Julian and Gregorian calendar?
The Gregorian calendar is only a minor modification of the Julian calendar. The main difference between the two calendars is the number of days in an average year. However, the two calendars feature two types of years, the leap year and the standard year which has 365 days.
GREGORIAN CALENDAR
Every year has an average of 365.2425 days
It’s the new style calendar invented in 1582 and currently used in most countries.
Leap years don’t always occur after four years. Every year divisible by 4 is a leap year. Similarly, years divisible by 4 and 100 and also evenly divisible by 400 are also leap years.
JULIAN CALENDAR
Every year has an average of 365.25 days
It’s a 365 days calendar invented in 46 B.C., only used by some orthodox states.
Had a leap pear in every four years
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I was looking for a pre-Julian calendar that could be juxtaposed with a modern Gregorian calendar including the Ides, Kalends nones and bi-sextile day. It would make a cool decorative and instructional object.