FUNCTION: time_tk_str = time_ticks(timerange,offset) NAME: time_ticks PURPOSE: Returns a structure that can be used to create time ticks for a plot. See "timetick" for more info INPUT: timerange: Two element vector specifying the time range of the plot this input can be obtained from: "time_double", "time_struct" or "time_string" offset: named variable in which offset time is placed. KEYWORDS: NUM_LAB_MIN: minimum number of labels for bottom axis. OUTPUT: a structure that can be used with the _EXTRA keyword of the PLOT routine See Also: "box", "tplot" NOTES: The returned time_tk_str has tags named so that it can be used with the special _EXTRA keyword in the call to PLOT or OPLOT. The offset value that is returned from timetick must be subtracted from the time-axis data values before plotting. This is to maintain resolution in the PLOT routines, which use single precision floating point internally. Remember that if the CURSOR routine is used to read a cursor position from the plot, this offset will need to be added back to the time-axis value to get seconds since 1970-01-01/00:00:00. NOTE: This routine is an enhanced version of the routine "timetick" See this routine for more info on usage WARNING!: This routine does not yet work on very small time scales. CREATED BY: Davin Larson Oct 1996 FILE: time_ticks.pro VERSION: 1.16 LAST MODIFICATION: 02/04/17