Well depending on the year Steven was born, and how old he is and we know that, Steven is 14 years old, and that means born in 2002 correct, so we take how old he was when he meet the gems, and that is 22 and what year we was 22 in is unknown but sour cream was a baby durning that so he was probably 1 year old at that time, so we can figure out both sour creams and Gregs age is we figure out what year it was the this episode took place. And I think we know, it was the 1980s right, so we just figure out his age in this episode, and that was probably 25 so what was it well then we need to look at when Greg said that mud-nato was and that was 15 years ago, so we have 22, 14, 15 and 1980, so let's see, Greg got the job during the year 1986 becuase I rewatched the episode. Looked up the phone Vidalia was useing when she got the call, and most pics and things match that phone to that year. So with this and a couple other things that match that years tech, so if Greg got the job in the year 1986, that means we need to talk happend a couple years earlyer and the same with story for Steven, I lead those two episodes happening in the same year, that year being 1983 So if this all added up, if Greg was 22 in the year 1983, three years later he was 25 in this episode, the year 1986, and that is 14 years before the year 2000, so he is 39 in the year 2000 add two for the year Steven was born, and that is 41 years old at the year 2002, and finally add 14 years becuase it is 2016 in this episode, leading to Greg being 55 in current times, it does all add up, so Greg is 55 in the year 2016, if not he is atleast in his late 50s
It certainly makes sense and fits what he looks like! We can at least assume that "Story for Steven" and "Greg the babysitter" are nine months apart maybe a bit more looking at SC's development. The only issue that arises is that if SC was born in 1985/86 there abouts that would make him 30/31 in the present, and he does not look aged to 30. Of course this could all take place in the 90's for all we know, maybe the Gems never updated their appearance for a decade, or the timeline of the SU Earth is different from the real Earth.