My days originally have had 7 hours. The school said a thing and I thought I should include a plus hour, before the original 7 hours.
I added it (0. hour) and I saw the hour of all time constraints updated: increased by 1.
I know many times it's a good feature but in my case (I've record all activities, time constraints) hasn't increase. My 0. hour is like an virtual hour.
Now I can manually rewrite the .fet file but I think it would be nice when user can disable this feature - maybe FET ask about it the user when add later (means there are time constraints) a new hour.
I added this in the TODO, but unfortunately it is too complicated and risky. I should think of adding/removing days/hours, maybe even in the middle of the existing activities, not only as first value.
The current approach is that a constraint in FET has an integer value, not the name of the day/hour. So this is why if you simply modify the .fet file by hand you can overcome this problem.
I am sorry. I don't know a better/simpler approach.
I think this functionality becomes simpler with TiTiTo.