Can you combine multiple time-independent I/O API files as one time-dependent I/O API file?

I/O API m3tools
1

I have four time-independent CALC_TMETRIC* files (CMAQ-postprocessed), one for each season, and I am trying to combine them into one file with four timesteps for each season. Using m3cple four times (with the CALC_TMETRIC* files as input each time) did not work - only the last file copied would be in OUTFILE, which would also be time-independent.

2

For this one, you probably need to write custom code; you might want to follow the “standard year” conventions from https://cjcoats.github.io/ioapi/DATETIME.html:

most of the data is for year 0, but include time-step for year -1 and another for year 1, with time steps centered on the season-center so that you can use INTERP3 to get smoothly-varying values, and you can use NEXTIME to get the dates&times (it still works for these dates&times, and with negative time steps when you need it):
TSTEP = 91 1/4 days = 21900000 (H* MMSS)
Step # 2 is at Feb. 6 (0000037:000000) and you can use

TSTEP=21900000
JDATE=37
JTIME=0
CALL NEXTIME(JDATE,JTIME,-TSTEP) !! to get the starting date&time

DO N = 1, 6
     ...
    CALL WRITE3(FNAME,VNAME,JDATE,JTIME,BUFFER)
    CALL NEXTIME(JDATE,JTIME,TSTEP)
END DO

to loop through these time steps.