I think I have you slightly beat… mine was an Apple II+, circa late 1981, with a disk drive, and a monochrome green screen monitor.
First cell phone was around 1997. Though I honestly don’t remember what it was. I recall having a Nokia model from before they made that indestructible model in all the memes, as well as a Kyocera one that I could connect to a laptop and have wireless dial up internet at some abysmal speed like 20 kbps. (0.02 mbps). I had at least two more phones, including a Treo 650 “smartphone” before getting my first iPhone, a 3G. I’m on my sixth iPhone now.
Sandford Fleming (the guy who invented time zones) actually made it easier.
Before timezones, every town had their own clock that defined the time for their town and was loosely set such that “noon is when the sun is at its highest point in the sky.” Which couldn’t be measured all that accurately.
If it wasn’t for Fleming, we’d be dealing with every city or town having a separate time zone.