When does the program withdraw the expenses for the year? Is it on your birthday? At the beginning of the year? When exactly is it programmed to come out - or add investments/cash infusions?
Expenses come out “today” for this year.
Since everything is annual we either take it now at beginning of year or at end of year.
If we did end of year, retirees starve until they get their money at the end of the year.
Soooo everything is beginning of year.
Nothing is done on the birthday at all. The program asks “what year is it today”
and then asks one year from today “what year is it”. And on those days it also asks
“how old is the client or user”.