Date Format

Hi Everyone

I am using a userform textbox to enter data into a spreadsheet. I have the user enter the date as dd/mm/yy. Sometimes the date once enteried into the cell is dd/mm/yy and if you double click in it the format is dd/mm/yyyy. Other times it is dd/mm/yy. Can anyone suggest a solution so that the date format remains dd/mm/yy for every entry.

Thanks in advance
Tee