jul2greg
Converts a Julian day to a Gregorian date.
Prototype
function jul2greg ( julian : double or integer ) return_val [see return section] : integer
Arguments
julianA mult-dimensional double or integer array. The array type determines the form of the return value. See the return value section for details.
Return value
The structure of the return value is dependent upon the type of julian. If julian is a double, then a dimsizes (julian) x 4 array is returned where element 0 is the year, 1 is the month, 2 is the day, and 3 is the hour. If julian is an integer, then a dimsizes(julian) x 3 array is returned, where element 0 is the year, 1 is the month, and 2 is the day. The type is integer in both cases.
Description
Converts a Julian day to a Gregorian date. A Julian day is defined as the number of days since January 1, 4713 B.C. A Julian day begins at noon Universal Time [UT: 12Z] of the given date (Fliegel & Van Flandern, (1968), A Machine Algorithm for Processing Calendar Dates, Communications of the ACM 11 No. 10, p657)
Examples
Example 1
i = jul2greg(2415020 ) ; ==> i(0)=1899, i(1)=12, i(2)=31
j = jul2greg(2415020.5) ; ==> j(0)=1900, j(1)=1, j(2)=1, j(3)=0
j = jul2greg(2415020.75) ; ==> j(0)=1900, j(1)=1, j(2)=1, j(3)=6
j = jul2greg(2415021. ) ; ==> j(0)=1900, j(1)=1, j(2)=1, j(3)=12
j = jul2greg(2415021.25) ; ==> j(0)=1900, j(1)=1, j(2)=1, j(3)=18
year = (/1950,1960,1970,1980,1990,2000,2500/)
month = (/ 1, 1, 1, 7, 1, 1, 12/)
day = (/ 1, 1, 1, 15, 1, 1, 31/)
hour = (/ -1, -1, -1, -1, -1, -1, -1/)
ymd = jul2greg(julim)
; returns
; (0,0)1950 (0,1)1 (0,2)1
; (1,0)1960 (1,1)1 (1,2)1
; (2,0)1970 (2,1)1 (2,2)1
; (3,0)1980 (3,1)7 (3,2)15
; (4,0)1990 (4,1)1 (4,2)1
; (5,0)2000 (5,1)1 (5,2)1
; (6,0)2500 (6,1)12 (6,2)31