JD2MJD

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Description

Converts Julian Date to Modified Julian Date

Arguments and Return Values

Parameters: Numeric array specifying the Julian date

Return Value: A double-format numeric array with the same organization as the inputs

Usage

Syntax: JD2MJD(JD)

The Julian Date is a continuous count of days since noon UTC on January 1, 4713 BCE in the proleptic Julian calendar. The Modified Julian Date is a continuous count of days since midnight UTC at the beginning of November 17, 1858 (in the Gregorian calendar). An offset of 2400000.5 is the only difference between the two. This function just subtracts that offset.

When JD2MJD() is entered without any arguments, it prints its description, as shown below.

Examples

dv> JD2MJD()

Convert Julian Date to Modified Julian Date
Works for array inputs
JD2MJD(JD) returns the Modified Julian Date.
Returns double-precision Modified Julian Date
S.Marshall 06-28-2008

0
dv> JD2MJD(2400000.5)
0.00000000000000
dv> JD2MJD(2400001)
0.500000000000000
dv> JD2MJD(0)
-2400000.50000000
dv> JD(clock(1))
2455181.35159387
dv> a = clock(1)
7x1x1 array of double, bsq format [56 bytes]
2009.00000000000        12.0000000000000        15.0000000000000        13.0000000000000
26.0000000000000        30.3284120000000        -7.0000000000000
dv> JD(a)
2455181.35173991
dv> MJD(a)
55180.8517399122
dv> JD2MJD(JD(a))
55180.8517399123

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Related Functions

Recent Library Changes

Created On: 11-18-2009
Modified On: 05-07-2010

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