Yeah the calendar has been a pain! I made a forum post a few days ago outlining some real headaches with FMS’s documentation on the matter
What I’ve done in the automated pipeline is to reset the calendar of all my forcing files to be DAYS SINCE your experiment start date. I don’t yet know whether this will mess other things up, but at least it handles issues related to calendar type (unless, god forbid, you trip to run your model on an actual leap year)
I haven’t automated data_table modification for IAF runs though and probably won’t. It would be awesome if someone put this functionality into the pipeline though!