More Words, Deeper Hole

The UK has a cremation rate of about 75% so about three quarters of the dead definitely aren't going to be rising even of those buried only fairly recent corpses can rise due to decomposition. Obviously once
you know what is happening then quick cremation becomes compulsory.

I never thought that the situation in Night of the Living Dead was even remotely compatible with Dawn of the Dead or Day of the Dead. The group in night of the living dead had the extremely bad luck to be isolated in a rather flimsy building right next to several cemeteries, so were under exceptionally heavy attack with exceptionally poor defences. Nearly everyone else would be in a far better situation to survive the initial outbreak and the zombies themselves were slow mindless not that numerous (limited to fresh non-cremated corpses) and effectively defenceless against any kind of organised attack. The existing living dead would be eliminated in a few days and cremation would become compulsory. For Dawn of the Dead and Day of the Dead to work most of humanity would have had to die first, maybe due to a plague, only later rising as zombies and attacking the tiny immune minority after organised society had collapsed due to a plague.