The ideal length of a seminar is two to three days. Participants feel that one day is not enough and that four days keeps them out of the classroom too long. It is preferable to not schedule multiple day seminars on consecutive weeks. It is preferable to schedule multiple day seminars on different days of the week.
Participants find that meeting on the same day of the week makes it difficult to miss classes.
It is best not to schedule seminars the week before and after Thanksgiving, Christmas, Winter and Spring breaks. It is best not to schedule seminars past mid-May. Fridays tend to be a difficult day to arrange for substitutes. Be creative in your scheduling. For example, if your district has school-wide professional development days, try scheduling multiple seminars for that day.