Unable to convert date into monty year format

[#1]

I have a excel sheet and I would like to tell JMP that it is monthly data. Dates in the format of dd-mm-yyyy. How hard I tried, it is taking dd-yyyy. Any suggestions? 

[#2]

Try this formua:

new column("MonthYear", Input Format( "m/y" ), Format( "m/y", 10 ),formula(Date DMY( 1, Month( :ds ), Year( :ds ) )));