Rolling count between dates?

yvonne-c — Wed, 25 Nov 2020 16:16:04 GMT

Can anyone help with counting the data in this table (sample attached) into a table like the one below

All IDs have a 'dateon' which will be counted unless there is a 'dateoff'

So ID A will be counted within all months below as it has been present for all of these months

J would only be counted in Feb- Apr as it was not present after May

I just need the

Thanks!

topic Rolling count between dates? in QlikView