ASP obtains the code for the first and last days of the previous month, this month, and next month.

First day of last month: <% = dateadd ("m",-1, year (date) & "-" & month (date) & "-1") %>
Last day of last month: <% = dateadd ("d",-1, year (date) & "-" & month (date) & "-1") %>
First day of this month: <% = year (date) & "-" & month (date) & "-1" %>
Last day of the month: <% = dateadd ("d",-1, dateadd ("m", 1, year (date) & "-" & month (date) & "-1") %>
First day of next month: <% = dateadd ("m", 1, year (date) & "-" & month (date) & "-01") %>
Last day of next month: <% = dateadd ("d",-1, dateadd ("m", 2, year (date) & "-" & month (date) & "-01") %>