Epoch Calculator

EPOCH CALCULATOR

Current Gregorian Date:

Current Julian Date:

Current Modified Julian Date:

Current J2000 Epoch Date:

Convert Epoch Date Format

(Please provide an input in at least one field.)

Epoch Calculations

Gregorian Date and Time:

Julian Date:

Modified Julian Date:

J2000 Epoch Date:

NOTES

An epoch in astronomy is the reference time used for consistency in calculation of positions and orbits. Common astronomical epochs include Julian Date, Modified Julian Date, and J2000.

Gregorian Date

The calendar system most used today. The system was introduced in 1582 to correct inaccuracies in the Julian Calendar.
  • Aligned with the solar year to ensure seasonal consistency.
  • Utilizes "year", "month", and "day" format.
  • A year is 365 days, with a leap year every 4 years.
  • Months have varying lengths (28-31 days).

Julian Date (JD) Epoch

A continuous count of days that is useful for astronomical calculations as it eliminates complications of months and years.
  • Starts from 12:00 UTC on January 1, 4713 BCE.
  • Expressed as a decimal number to represent fractional days.
  • e.g., 2451545.0 corresponds to January 1, 2000, at 12:00 UTC.

Modified Julian Date (MJD) Epoch

A simplified version of the Julian Date, introduced for convenience in some scientific and technical fields.
  • Starts from 00:00 UTC on November 17, 1858.
  • MJD = JD - 2400000.5

J2000 Epoch

A standard epoch in astronomy that is used as a reference point for celestial coordinates and astronomical phenomena.
  • Starts from 12:00 UTC on January 1, 2000.
  • Expressed in Julian Date as 2451545.0..

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