There was an OCA parish where I used to live which started a diaconate program a few years ago that was associated with St. Tikhon's Seminary. The diaconate program may have been thought of in part as a "late vocations" program, but in actuality there were older (50+) and younger (20s - 30s) men enrolled. The younger men that I knew in the program were married with children and/or established already in a career. For them, it would be very difficult to drop everything and go to seminary for a couple of years, and they may have been "testing the waters" to see if God may be calling them to seminary. The way this program was designed, those enrolled would attend classes at the church all day every Saturday (I'm sure they had some breaks). The day would begin with Divine Liturgy and end with Great Vespers, with those enrolled playing an active liturgical role (in the choir, serving in the altar, etc.). After two years of attending these classes and completing associated assignments and tests, the participant in the program would be considered by St. Tikhon's Seminary to have completed the equivalent of one full year of seminary. After the completion of the two year program, one's bishop may decide to ordain him to the diaconate. Or, after two years in this program one may decide to go to St. Tikhon's Seminary for two years (rather than the usual 3) to receive an M. Div. Or, after the completion of the course one could just continue among the laity without ever being ordained.