Julian Day Calendar For 2025. 2025 calendar with modified julian date (mjd) and gps week:day numbers return to leapsecond.com home page. Use this tool to convert between date and julian (yyddd) date formats.
The julian calendar, also known as the old style calendar, was established by julius caesar in 46 bc, to replace the roman calendar which was in use. Enter a valid date or julian date, and click ‘convert’.