I have a list of Sales (column A) and a list of closing dates (Column B). On
a separate sheet, I have a summary page showing total sales closing within
30day,then 60days then 90days.

I was going to use the Sumif functions =sumif(B1:B1000, criteria, A1:A1000)
but I can't figure out the criteria formula for each of the 3 periods.