How to impose a time slot for certain meetings

If you wish to allocate specific slots to certain meetings, please do so before starting the automatic placement.

In the display Parent/Teacher meetings > Meetings > Meetings' grid, select the meeting from the list, click and drag the green frame to the chosen slot, then double-click to place the meeting.

Once the meeting has been placed, right-click and choose Lock so that EDT doesn't move it during automatic placement.