Julian Day Calculator
Calculate Julian Day Number (JDN) for any calendar date. Shows Julian Date, Modified Julian Date, Reduced Julian Date, Dublin Julian Date, day of week, and J2000.0 epoch difference for astronomical use.
How to Use Julian Day Calculator
Enter a date (year, month, day) and optional time in UT. Click Calculate to see the Julian Day Number, Modified Julian Date, and other astronomical time references. Use the 'Use Now' button to fill in the current date and time.
Step-by-Step Instructions
- Enter year, month, and day
- Optionally enter hour and minute in UT
- Click Calculate to see Julian Day values
- View JDN, MJD, day of week, and J2000.0 offset
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