Compute useful times from a PAS image name. In Mar2020 this code was modified to handle images with non-standard PAS filenames. In this case, the code looks for the headercard with keyword "ACMBASE". This is the basename of the original PAS image. This card is filled by the acm processing code paga. If and image has no standard name and no ACMBASE card, then three values of "0.0" are returned.

pas_times.sh:
Get floating point dates from a PAS image name.

The times sent to standard out are: 
 col1  =  time in days since Jan1(UT=0) of Year=2000.0 
 col2  =  time in days since Jan1(UT=0) of cirrent year 
 col1  =  number of hours since UT=0 for current day 

Usage: pas_times.sh /home/sco/acm/20170906T074533.8_acm_sci.fits N 
arg1 - name of FITS image from PAS 
arg2 - verbose mode (Y/N)  

Examples:
% pas_times.sh /home/sco/HET_work/acm_nights/20170906/acm/20160101T001036.0_acm_sci.fits N 
   5842.507324    0.007521    0.18051   (days_since_2000,days_since_jan1,hours_since_UT=0)

% pas_times.sh /home/sco/tmp2/local_red/ISET_STACKS/iset_2_stack.fits N  
   7237.623047  299.123291    2.95886   (days_since_2000,days_since_jan1,hours_since_UT=0)

% pas_times.sh /home/sco/tmp2/local_red/ISET_STACKS/no_real_name.fits N  
 0.0 0.0 0.0     (days_since_2000,days_since_jan1,hours_since_UT=0)

In late Mar2020, and then again in July 2020, I decided that outputting the date string was useful. In order to avoid problems with downstream scripts that use the output from pas_times.sh, I created a fixed-format output file that (always named "pas_times.dat") that has the date and the information above. Here is an example:

% pas_times.sh /media/sco/DataDisk1/sco/AD/HET_work/acm_nights/20191113/acm/20191113T224225.8_acm_sci.fits N 
   7255.446289  316.946136   22.70717   (days_since_2000,days_since_jan1,hours_since_UT=0)
% cat pas_times.dat 
20191113    7255.446289  316.946136   22.70717 2019 11 13   (UTdate,days_since_2000,days_since_jan1,hours_since_UT=0,year,mon,day)