Institut für Astronomie und AstrophysikAbteilung AstronomieWaldhäuser Str. 64, D-72076 Tübingen, Germany |
GET_JULDATE
Return the current Julian Date
This procedure became partially obsolete with the introduction of the /JULIAN keyword to the intrinsic SYSTIME function in IDL V5.2. Note however, that SYSTIME(/JULIAN) always returns the *local* time, whereas for most machines, GET_JULDATE returns Universal Time (i.e. Greenwich mean time.) In V5.4, GET_JULDATE became completely obsolete with the introduction of the /UTC keyword to SYSTIME(). So GET_JULDATE,jd is equivalent to jd = SYSTIME(/JULIAN,/UTC).
GET_JULDATE,jd
None
jd = Current Julian Date, double precision scalar
Return the current hour, day, month and year as integers IDL> GET_JULDATE, JD ;Get current Julian date IDL> DAYCNV, JD, YR, MON, DAY, HOURS ;Convert to hour,day month & year
The systime(1) function is used to obtain the number of days after 1-JAN-1970. The offset to Julian days is then computed. WARNING! This procedure assumes that systime(1) returns the value of Universal Time (UT). This appears to be true for most Unix workstations and DOS machines, but not for VMS or Macintoshes, for which systime(1) returns the local time. Users may need to add the difference between UT and local time to the value of JD, depending on the particular installation.
Written Wayne Landsman March, 1991 Converted to IDL V5.0 W. Landsman September 1997
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