I actually found out the answer myself, 18 months = 548 days, 13 months
= 396 days, 15 months = 457 days. I tried it many times and the numbers
are correct so I simpled it down to the following code: var date =
Date2Num(StartDate.formattedValue,"DD/MM/YYYY")EndDate.formattedValue =
Num2Date(date+548,"DD/MM/YYYY") I am stumped again on the drop down list
and will post the question in a separate post.