What times do you need at the end of a level for a firework so I can avoid them

Any time ending with the 2 last digits as the same number. So if the time is 455 you will get fireworks because it ends in 55.

so basically avoid your last 2 digits on the timer being 00, 11, 22, 33, 44, 55, 66, 77, 88, or 99. every other time will avoid fireworks

Why would you not just google this

yep the double digit in the timer, happends in some other games too like in nsmb for ds actualy yea seem to be kind of a simple info to search in google with a few words instead of having to wait for somebody to respond a thread lol