The virtual classes are of different lengths and formats. Each instructor has set up times and the number of instruction hours based on those of an in-person class. A teaching day is six hours. For a virtual four-day class, there are 24 hours of teaching time. Those hours could be in one, two, or three-hour blocks, as many as needed to make up the required number of hours. Teaching time may be live on Zoom or Groups.io, prerecorded, or whatever method the teacher has established.
Virtual classes have a postage charge for the mailing costs. Many instructors cannot accept international students because of the high postage rates and the difficulties of obtaining supplies elsewhere.