It can be like the first minute of that day but it is *horrifically* bad business practice and you will literally never see this in retail and if you do, should never give them your service again. Imagine if you had a flyer for Safeway, Sobeys, Save-On, Bestbuy, Walmart, Superstone, LITERALLY ANY RETAIL, and go in to purchase on the last day of the last day effective on that flyer, only to have them say "Sorry, the sale actually ended before we opened our doors today" - They would never be getting another penny from me, forever.
Not that you said it, but I don't want to hear that companies reserve the right to end the sale whenever and all of that stuff either. Proper companies will go out of their way to keep a customer and again, its bad business practice to do stuff like yeeting a sale before its finished and it's really telling how much a company values you if they do it. This isn't a physical product that sells out or a finite resource, there is literally no reason to not honor that price til end of day or end of operation on that day, unless they're just really anxious to roll in the garbage value plans that you can get with any other flanker carrier.
