If you need to perform calculations on the value (sum, average, max, min, etc.) then store it as a number. You can always display it with whatever format you want. For example, to force a number to display with two digits make the format 00. In a query or VBA you can say:

Format(MyValue,"00")

If you don't need to perform calculations, then you can use short text and save it however you want.

What I want to do is measure the length for example If Len(BirthMonth)2 Then...  The problem is not all months are two-digits.  I tried Len(Format (BirthMonth, "00"))2  but no effect...  What do you recomend?

Why use the length for a numeric field when a normal inequality will do just fine?

If BirthMonth<10 then ...

What are you trying to do?

Same old problem.  on an OnChange event     If BirthMonth  9 Then BirthDay.SetFocus.  It doesn't understand that when I type 01 that's it.  when it defaults back to 1, it thinks it could be 10,11,12....etc.  I want it to know that 01 is two digits, therefore, go to next field.

I'm still not understanding why you need two digits. Sorry! If you want to display it with two digits, then just make the format: 00

I want it so when it measure that tw0 digits are entered (be it 01 or 11) that it will auto tab to next cell.  It works great in months October, November and December.  On months 01 to 09, however, it expects another digit even though I types in 09 for example.

OK, how about:

If Len(CStr(MyField))>=2 Then ...

Convert the field to a string first, then check its length?

Still No dice.  It ignores the 0 before any number and doesn't count it as a digit.  For what it's worth this would be a great tutorial for moving a cursor to the next field after you type so many numbers.

Let me get this straight though... you want to STORE the data as a number, but DISPLAY it as 01, 02, 03, etc. Also, as soon as you type in TWO digits, you want the focus to move to the next field. Is that correct?

That is correct!

OK. You got it. There's an easy way and a slightly more complicated, but more flexible way. You'll be today's TechHelp video. Stay tuned...

Thank you

Your video is ready: AutoTab to Next Field