If I attend the DMDL or G4L program part-time, how long will it take me to finish?

The M.A. program is typically four semesters full-time, so it would be eight semesters half-time, or (conceivably) 16 semesters quarter-time. The advanced certificate program is approximately one semester shorter.  Depending upon what courses are offered in the summer or winter that can be applied to the degree, it may be possible to complete the program in a shorter period of time, part-time.