I am curious as to how long, in terms of hours/days, it took for the flash to become visible and then extinguish? The article makes it seem like it was over a

I am curious as to how long, in terms of hours/days, it took for the flash to become visible and then extinguish? The article makes it seem like it was over a day or two, but is that generally how long a supernova event will take? I was of the belief that it was a very brief event lasting only an hour or so?