Changing Routine

I know people say chins get used to a set routine and what not, so I try not to change things around on them if I don't have to.



I've always refilled food/water/hay and given a treat between 3:30am - 4am every morning.



However, now I am working 2 jobs and most days I'm at both jobs. So I was thinking about switching the routine and start refilling food/water/hay and giving a treat at 11pm.



how sensitive are they to routine changes?