I real life land it isn't practical to plan all your maintenance for a single day because that doesn't make full use of your maintenance staff who probably expect 40 hours of work per week. In airway sim Saturdays are slow, for whatever reason, so its generally most efficiency to plan maintenance for Saturdays. Is there any reason not to do this in the sim or is it best just to plan all A and B checks for Saturday?
Plan when they are the best, which is on saturday, most of the time(unless you toy with 7-day schedule). Don't worry about maintenance concentration.