If you are at one site for a month do you need to adjust the system at any time during the stay?
When my unit is in my shop here at home, I sometimes use my auto level and leave it in place for a good while and then change it up to only the front jacks, etc. During those extended periods, sometimes it will get one degree or so off one way or the other. If I find it like that, I will put it in manual mode and give it a small bump.
I agree with Dave that for most units, it shouldn’t need anything most of the time. I think that the more age a unit has, the more chance for small leaks.