Procedure: add_tt2000_offset Purpose: Takes TDAS double timestamp and offsets date(s) using the data in the CDF 3.4(or later) leap second config file. Like time_string and time_double, it is vectorized and accepts array inputs of arbitrary dimensions Inputs: Dates: If /subtract is not set: double precision seconds since 1970 TAI (Unix timestamp) Can be scalar or array values with any dimensions or ordering. If /subtract is set: double precision seconds since 1970 TT(timestamp TT 1970 epoch) can be scalar or array values with any dimensions or ordering Keywords: subtract: If this keyword is set, this function will subtract leap seconds from a TT date that already includes them. Offsets: Set this to a named variable in which to return the offsets used for the calculation. Note that these can differ in both sign and magnitude for a particular date, depending on whether you are adding or subtracting. Return Value: The data with leap seconds added(or removed). Notes: #1 This routine requires the CDF 3.4 leap second file. One will be provided with the TDAS install, but it will be updated automatically when a new leap second occurs. #2 The IDL system variable "!CDF_LEAP_SECONDS" must be defined for this routine to work. This variable is defined by calling cdf_leap_second_init. Normally, the initialization routine for missions that use tt2000 should use this. #3 The calculation adds both leap seconds and the 32.184 second historical offset between TAI and TT Examples: THEMIS> print,time_double('2007-03-23')-add_tt2000_offset(time_double('2007-03-23')) -65.183998 THEMIS> print,time_double('2007-03-23')-add_tt2000_offset(time_double('2007-03-23'),offsets=off_p) -65.183998 THEMIS> print,off_p 65.1840 THEMIS> print,time_double('2007-03-23')-add_tt2000_offset(time_double('2007-03-23'),offsets=off_s,/subtract) 65.183998 THEMIS> print,off_s -65.1840 $LastChangedBy: kersten $ $LastChangedDate: 2013-01-30 10:33:53 -0800 (Wed, 30 Jan 2013) $ $LastChangedRevision: 11501 $ $URL: svn+ssh://thmsvn@ambrosia.ssl.berkeley.edu/repos/spdsoft/trunk/general/misc/time/TT2000/add_tt2000_offset.pro $