datetime2num

The datetime2num function returns the Julian Date from a string like '2005-09-28T04:35:14.45' or 2005-09-28T04:35:14.45. Strings with enclosing ' ' are present in FITS image headers and are returned using CImage:KwdGetRaw.

NOTE:

You may wish to test if the string is a time value before calling this function to avoid the ambiguous results for datetime2num("0000-00-00T00:00:00") and datetime2num(0).

Syntax

nJD = datetime2num( sString )

sString is the target string.

nJD is the Julian Date.

On failure, 0.0 is returned.

Example

The scripts below return the Julian Date for several strings:

str = "'2005-09-28T04:35:14.45'"	-- date+time string with ' '
if is_datetime( str ) then
nJD = datetime2num( str)
Printf("JD = %.8f\n", nJD)	-- prints JD = 2453641.69113947
end

str = "2005-09-28T04:35:14.45"	-- date+time string without ' '
if is_datetime( str ) then
nJD = datetime2num( str)
Printf("JD = %.8f\n", nJD)	-- prints JD = 2453641.69113947
end

Printf("t = %.8f\n", datetime2num("Johnny"))	-- prints t = 0
Printf("t = %.8f\n", datetime2num(15.5))	-- prints t = 0

Syntax

Example

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