How do I fix m-yy date problem filling cell incorrectly?

[exceltm]

I have a spreadsheet of credit card expiration dates, such as 1-17 or 12-16. Im using Right Click, Format Cells, Custom, then setting m-yy. In the past this worked correct when I would insert new dates, but now it converts or posts them incorrectly. For example, if I type 1-17, it will convert it to 1-13 in the display and 1-17-13 in the underlying value. If I type 12-16, it will convert it to 12-13 and 12-16-13 in the underlying value. How do I fix this and what went wrong? It appears that its converting every month-year combination into the current year, which it shouldn't be doing.

 

[vogel997]

Just enter 12-1-16 and it will show 12-16
If you enter 12-16, excel assumes that you enter the month and day and then the year.