Start the free trial clock once the account is actually used.
Our organization has used Azure products to a small degree, but they have not been a part of my work. Yet. I desperately need to get myself more familiar with the line, but haven't had a business need to do so. To that end, because of my lack of familiarity, I'm not in a position to advocate for the use of Azure for anything, either. So it's a bit of a chicken-or-egg scenario. I created a free trial account, hoping that I would find the time to "play" with it. The account's about to expire and I haven't even touched it yet. At this point, I'm going to go crawl back into my "One of these days, Azure..." hole. Having the free trial expiration governed by something other than a straightforward time limit from when it was created would be more helpful to me.
Jason Thornbrugh commented
I completely agree. I want to get Azure certified but I got busy at work, so I never even used it. It took me 6 months of intermittent AWS use to get my AWS cert.
Kevin Kearney commented
Same here. You sign up as part of getting yourself ready to use it. Then you focus on other prep work.