Julian date converter for both common meanings.
Convert standard calendar dates into ordinal Julian codes, short production codes, and astronomical Julian day values. Reverse the ordinal format when you need the Gregorian date back.
Julian Date
Understand the difference between ordinal Julian formats and astronomical Julian day numbers, convert between formats, and browse reference charts by year.
Use the converter
The widget covers the common industrial format and the astronomical count in one place.
| Short Production Code | 26171 |
| Julian Day Number | 2461212 |
| Julian Date (UTC) | 2461211.75919 |
| Days This Year | 365 |
| 5-digit code | 26171 |
| Day of year | 171 / 365 |
| Julian Day Number | 2461212 |
| Julian Date at 00:00 UTC | 2461211.50000 |
2026 is not a leap year, so the valid range is 1 to 365.
| Weekday | Saturday |
| Full ordinal format | 2026-171 |
| Short production code | 26171 |
| Quarter | Q2 |
Worked examples
Examples make the format differences easier to spot than a bare formula does.
| Calendar date | ISO | Ordinal Julian | Short code | JDN | JD |
|---|---|---|---|---|---|
| Saturday, June 20, 2026 | 2026-06-20 | 2026-171 | 26171 | 2461212 | 2461211.75920 |
| Tuesday, June 9, 2026 | 2026-06-09 | 2026-160 | 26160 | 2461201 | 2461200.50000 |
| Thursday, December 31, 2026 | 2026-12-31 | 2026-365 | 26365 | 2461406 | 2461405.50000 |
What this page converts
The ordinal format writes a date as year plus day-of-year, such as 2026-171. The five-digit production version drops the century and becomes 26171. Those are the forms most often used on labels, batch codes, and operational checklists.
The astronomical system is different: it counts days continuously from a fixed epoch and is most useful in astronomy, orbital mechanics, and historical chronology. By keeping both outputs together, the converter handles the ambiguity that makes many “Julian date” search results confusing.
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