I know it was Sept 1993 because it was three months before I moved to the USA. Linus was already out there and very vocal by 1993. He started Linux a couple years before that. I was a newbie in a large swamp of hilarious people. One guy took a train from the south of the Netherlands (Limburg) for 3.5 hrs to help me suss out a HW issue with a PC I had just built. I drove him back home as thanks.
Those original people across the globe committed me to helping as much as I could back then when Microsoft was the Big Bad Nasty Meanie.
And here's the funny thing to me, many of my customers are fully dedicated to Microsoft Azure cloud but I ALWAYS put all of their infrastructure on Linux. Linux has about 65% of all VMs and dedicated HW instances in Azure as of Dec 2020.