Danish Personal Identification Number (CPR-number)

\b(?:0[1-9]|[12][0-9]|3[01])(?:0[1-9]|1[0-2])[0-9]{2}-?[0-9]{4}\b

Matches a string of the format NNNNNN-NNNN, where the first and second digits begin with [01–31], third and fourth digits begin with [01–12] and the fifth and sixth digits begin with [00–99].

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