booter, forget it :-) Even treating the date as a string, you'd have problems.

Quite apart from trying to parse something like '310919':

1. Could it be ddmmyy? No (31 > days in Sept)

2. Could it be mmddyy? No (31 > months in year)

3. Could it be yyddmm? No (19 > months in year)

4. Could it be yymmdd? Yes! (1931:Sept:19)

treating user input as a:

"numberic [which] cannot start with 0"

raises so many issues that IMO it would be better to rethink your 'pin number' concept.

How, for example, are you going to prompt for user input?:

   Enter your birthday in any format:
         yyyymmdd
         yyyyddmm
         yymmdd (unless your birthday is between 1900 and 1909, or sin
+ce 2000)
         yyddmm (unless your birthday is between 1900 and 1909, or sin
+ce 2000)
         ddmmyyyy (unless your birthday is before the 10th of the mont
+h)
         mmddyyyy (unless your birthday is between January and Septemb
+er)
         ddmmyy (unless your birthday is before the 10th of the month)
         mmddyy (unless your birthday is between January and September
+)
[download]

How to explain that if the user's birthday is '030303', they have no choice but to enter '19030303' (if they're very old) or '20030303' (if they're very young)??

There must be a better way to do it!

dave