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gmt_offsec.pro
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gmt_offsec.pro
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;-------------------------------------------------------------
;+
; NAME:
; GMT_OFFSEC
; PURPOSE:
; Return offset in seconds from local time to GMT (UT).
; CATEGORY:
; CALLING SEQUENCE:
; off = gmt_offsec()
; INPUTS:
; KEYWORD PARAMETERS:
; OUTPUTS:
; COMMON BLOCKS:
; NOTES:
; Note: Times are rounded to the nearest 1/4 hour.
; This should handle any time zone, even fractional ones.
; MODIFICATION HISTORY:
; R. Sterner, 2 Dec, 1993
;
; Copyright (C) 1993, Johns Hopkins University/Applied Physics Laboratory
; This software may be used, copied, or redistributed as long as it is not
; sold and this copyright notice is reproduced on each copy made. This
; routine is provided as is without any express or implied warranties
; whatsoever. Other limitations apply as described in the file disclaimer.txt.
;-
;-------------------------------------------------------------
function gmt_offsec, help=hlp
if keyword_set(hlp) then begin
print,' Return offset in seconds from local time to GMT (UT).'
print,' off = gmt_offsec()'
print,' off = offset in seconds from local time to GMT (UT).'
print,' Note: Times are rounded to the nearest 1/4 hour.'
print,' This should handle any time zone, even fractional ones.'
return,''
endif
jsg = systime(1) + dt_tm_tojs('1970 Jan 1') ; GMT Julian Seconds.
jsl = dt_tm_tojs(systime()) ; Local Julian Seconds.
diff = jsg - jsl ; Diff in seconds.
return, round(diff/900.)*900. ; Time to nearest .25 hr.
end