Create checks, that the CII date format is verified

[phax]

Source: https://github.com/itplr-kosit/validator-configuration-xrechnung/issues/56

Please check that the format attribute is only 102, 610 or 616

Check the 102 format like this:

• Length must be 8
• All chars must be numeric
• Year must be > 0
• Month must be >= 1 and <= 12
• Day must be >= 1 and <= 31

A regular expression for this may look like this:

^[0-9][0-9][0-9][1-9](1[0-2]|0[1-9])(3[01]|2[0-9]1[0-9]|0[1-9])$

[oriol]

Applying regular expression (20\d{2})(\d{2})(\d{2}) to udt:DateTimeString[@format = '102']

[phax]

I don't like the fix 20 in front. Wouldn't it be simpler (and less error prone) to use \d{8} instead?

[oriol]

You are right.