Be very careful is right.
On double digit months, my keying tool accepts the first digit (1) but you must choose from the drop down box for the second digit.
For instance, the 12th month. if you type 12 in the box without regard to the drop down box you get "10" because the digit "2" is achieved by pressing "4".
type 0 you get nothing and if your not paying close attention you may tab by and only have the first "1"in the box.
type 2 you get 0
type 3 you get 1
type 4 you get 2
Once I got the hang of it I survived but it is kinda cheap.