I am testing two variables of similarly named and sequentially
numbered through a do..loop.

I know that I can do that via var() array.

but if I want to change the variable name via string changes, how to
do it?

........
day_1 = date
day_2 = dateadd("d", 7, day_1)

nn=1

do
msgbox "day_" & nn ' not working this way,
nn= nn+1
loop until nn=3

.............

........