Our neighbours do the same thing here. Any time of day or night.
One, lights several small fires at a time, on his land.
Another one never takes anything to the bins, so burns everything, plastic etc. etc.
When we are about to burn anything, we go round to the next door neighbour and ask them to take any washing indoors.
But, they don't bother if they burn, and my washing is out.
Bet these people don't have any licences anyway!