How to Convert JD to MJD
To convert jd to mjd, multiply the value by 1.
The Formula
MJD = JD × 1
Key Fact
1 julian day = 1 mjd
Tip: To convert mjd back to jd, divide by 1.
Julian Day to Modified Julian Day
Convert jd (JD) to mjd (MJD) with formulas, examples, and conversion tables.
JD
MJD
1 JD = -2399999.5 MJD
Full precision:-2399999.5 MJD
Step-by-Step Solution
To convert 1 jd to mjd, we multiply by 1 because one julian day equals exactly 1 mjd.
1 julian day = 1 mjd
Since each julian day contains 1 mjd, we multiply our value by this factor:
1 × 1 = -2399999.5 mjd
So 1 jd = -2399999.5 mjd.
Quick check: -2399999.5 ÷ 1 = 1 jd
Example Conversions
Example 1: 1 JD = -2399999.5 MJD
1 × 1 = -2399999.5
1 × 1 = -2399999.5
Example 2: 5 JD = -2399995.5 MJD
5 × 1 = -2399995.5
5 × 1 = -2399995.5
Example 3: 10 JD = -2399990.5 MJD
10 × 1 = -2399990.5
10 × 1 = -2399990.5
JD to MJD Table
| JD | MJD |
|---|---|
| 0 JD | -2400000.5 MJD |
| 86400 JD | -2313600.5 MJD |
| 604800 JD | -1795200.5 MJD |
| 1765163406 JD | 1762763405.33 MJD |
1 Julian Day in Other Units
| Unit | 1 JD = |
|---|---|
| Julian Day to Unix Timestamp | -2.1087e+11 Unix |
| Julian Day to ISO 8601 | -2.1087e+11 ISO |
| Julian Day to Modified Julian Day | -2399999.5 MJD |
| Julian Day to Excel Serial Date | -2415017.5 Excel |