1, I have to use
date(now())-1to get the first day of the month.
date()integer (minus one) of the Date property from the Date property itself. We have to subtract one from the
date()output in order to get to the 1st of the month - there's no 0th day of the month!
date()'s output, as we want to go one day further backwards from the 1st of the month.