Aaron Sica and I have had this conversation a lot.
When MG '90 premiered, I forever thought it aired at 10 am on WVEC. Aaron - who vacationed in my neck of the woods in summer 1990 - always reminds me MG was originally at 10:30. My confusion came from the fact that September was when it moved to 10, making room for Trump Card at 10:30.
I also thought that if a network show aired at whatever Eastern time, that it automatically aired three hours behind in the Pacific time zone. I distinctly remember asking my aunt if people in Cali got MG at 7:30 am.
Yep! I still remember being so pleasantly surprised that WVEC carried it. When I saw a 10am show that was a half hour, I crossed my fingers that maybe - just maybe - they'd slot MG90 at 10:30. I remember being so happy when I saw that they did.
Regarding the time zones - I think I actually learned time zones, believe it or not, from Nickelodeon! Back in 1982 when there was only one feed, they actually announced each time zone's time and displayed it on the screen with whatever show they were advertising.
I had no idea of the West Coast daytime TV setup until my first LA TV Guide in 1984, and that out there, the daytime schedule went 9am-3:30pm, instead of 10am-4:30pm.