Defrost timers
GE use this defrost timer throughout the 70s on most of their frost free refrigerators, if you figure a refrigerator runs about 50% of the time a six hour cumulative timer like this with frost about twice a day.
During the same. Whirlpool used a continuous running timer with a 12 hour interval between defrost so they defrosted 12 hours a day definitely, the only thing good about the GE is if the refrigerator recent very cool environment where did run much he would actually defrost less than see the whirlpool going to defrost twice a day when you even open the door once or not
In either case, it was just more defrosting and was needed, except in a heavily used refrigerator with a large family and no air conditioning, etc.
John