Template talk:MJD2sec

Talk page for {{MJD2sec}} and {{sec2MJD}}

Documentation

Posix timestamps count seconds since 1970-01-01T00:00Z, negative values indicate timestamps before this date.

Usage

• {{MJD2sec|mjd}} converts a Modified Julian Date to a Posix timestamp.
• {{MJD2sec}} gives the current Posix timestamp.
• {{sec2MJD|sec}} converts a Posix timestamp to a Modified Julian Date.
• {{sec2MJD}} is a sanity test, it should be the same as {{MJD}}.

Examples

• {{MJD2sec}} = 1735147047
• {{MJD2sec|{{MJD|1970}}}} = 0
• {{MJD2sec|{{MJD|1970|01|02}}}} = 86400
• {{MJD2sec|{{MJD|1971}}}} = 31536000
• {{sec2MJD|1.000}} = 40587.000011574
• {{sec2MJD|1.001}} = 40587.000011586 (no milliseconds, sorry)
• {{sec2MJD|1.010}} = 40587.00001169

Critical POSIX timestamps (31/32 bits rollover)

Timestamp	MJD	MJD2sec	sec2MJD	comment
1901-12-13 20:45:52	15731.865185185	-2147483648	15731.865185185	-2^31
2038-01-19 03:14:07	65442.134803241	2147483647	65442.134803241	2^31-1
2038-01-19 03:14:08	65442.134814815	2147483648	65442.134814815	2^31
2106-02-07 06:28:15	90297.269618056	4294967295	90297.269618056	2^32-1
2106-02-07 06:28:16	90297.26962963	4294967296	90297.26962963	2^32

Optional substitution works for a specified parameter, examples:

{{ subst:sec2MJD2|1677283200|subst=subst:}} = 60000,

{{ subst:MJD2sec|60000|subst=subst:}} = 1677283200,

{{ subst:MJD2sec|{{ subst:MJD|subst=subst:}}|subst=subst:}}.

The third example is convoluted, but supporting optional substitution for a parameter default would make the MJD2sec code unnecessarily complex, and for sec2MJD it would be pointless.

See also

• template:MJD2sec (edit•talk•links•history)
• template:Sec2MJD (edit•talk•links•history)
• template:MJD (edit•talk•links•history)
• template:YMD2MJD (edit•talk•links•history)

Discussion

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