Mindy says it has been 8 months since they had seen her father. Mork responds by saying "that's 2.9% of our life together so far". At the time of this episode it had been about 16 months since Mork & Mindy (1978) had premiered, which means 8 months would be half of their lives together so far. Also, there is no chance a time warp of some because assuming that Fred & Cora went on the road after the events of Mork Runs Down (1979) it would about 8 months between the two episodes.