Julian Date Converter | YYDDD, CYYDDD & Excel Formulas

Julian Date Converter

Convert Gregorian, YYDDD and CYYDDD dates instantly.
Built for quick checks, spreadsheets, data work and operational systems.

Converter

Gregorian Date

Results

YYDDD

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CYYDDD

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YYDDD = 2-digit year + day of year • CYYDDD = century + 2-digit year + day of year

Paste multiple dates or Julian values, convert them in one batch, and copy the results straight back into Excel, ERP sheets or data tools.

Conversion Type

Results Date Format

Paste Data

One value per line. Empty lines are ignored.

Results

Results are returned one per line, ready to paste into spreadsheets.

Ready

Copy a formula into Excel to convert dates directly in your own sheets. The examples assume your source value is in cell A2.

Formula Type

Convert a normal Excel date in A2 to a 5-digit YYDDD value.

=TEXT(MOD(YEAR(A2),100),"00")&TEXT(A2-DATE(YEAR(A2),1,0),"000")

Example result: 26152

YYDDD uses the last two digits of the year followed by the day number within the year. Example: the 152nd day of 2025 becomes 25152.

CYYDDD adds a century digit before the year and day number. Example: 125152 means century 1, year 25, day 152.

JulianDate.net is built as a lightweight utility: fast loading, no account required, and focused on getting the right date value quickly.