If you apply different time grids for different types of schools, departments or single classes, this certainly has an effect on substitution planning. Working on substitution planning has not changed much, since suggestions for substitutions and preponements only include those teachers who can be assigned without any clashes.
You can earmark certain periods on certain days as "free periods". These periods always refer to the main time grid.
Absences are displayed/printed as HH:MM.
Break supervisions can be scheduled individually for any time grid. This is why substitutions of break supervisions are always carried out in the respective time grid.
Keep in mind that if you work with different time grids potential substitution teachers who do not teach in the respective period are not available because they are assigned to a break supervision in another time grid.
Like break supervisions, standbys and standbys for break supervisions can be scheduled for any time grid guaranteeing that sufficient standby teachers are available for any period.
Since the description of the period does not provide any clear information any more, the precise time of the substitution is displayed in the substitution print for the teachers. A second period can, for instance, start at 8:50 am or at 8:55 am, depending on the time grid in which the period to be substituted has been scheduled. In the substitution view, the "Time" column can be shown by clicking on <Grid adjustment>.
If you use several time grids, you cannot adjust the substitution dialogue window to "Teachers" any more, since the period is not clearly defined any more from the teacher's perspective.