Date of birth

Detects date-of-birth references in documents across multiple date formats (numeric slash, dot, hyphen, written month, ISO). Requires birth-record keywords in proximity to distinguish DOB from invoice dates, event dates, and other temporal references. No Microsoft built-in SIT exists for unstructured DOB detection.

Type: regex
Engine: boost_regex
Confidence: medium
Confidence justification: Medium confidence: date formats appear in every business document. Birth-record keywords are essential to distinguish DOB from the thousands of other dates in any corpus.
Jurisdictions: global
Regulations: GDPR, CCPA, HIPAA, PIPEDA
Frameworks: ISO 27001, ISO 27701, NIST CSF
Data categories: pii
Scope: wide
Risk rating: 7
Platform compatibility: Purview: Compatible, GCP DLP: Compatible, Macie: Compatible, Zscaler: Compatible, Palo Alto: Compatible, Netskope: Unsupported

Pattern

\b(?:(?:0?[1-9]|[12]\d|3[01])[\/.\-](?:0?[1-9]|1[0-2])|(?:0?[1-9]|1[0-2])[\/.\-](?:0?[1-9]|[12]\d|3[01]))[\/.\-](?:19|20)\d{2}\b|\b(?:19|20)\d{2}-(?:0[1-9]|1[0-2])-(?:0[1-9]|[12]\d|3[01])\b

Corroborative evidence keywords

DOB, date of birth, birth date, born, born on, birthday, d.o.b, d.o.b., address, age, citizenship, city, email, ethnicity, fax, first name, full name, gender, given name, last name (+14 more)

Proximity: 300 characters

Should match

Date of birth: 03/15/1990 — US month-first date
DOB 15/03/1985 — Day-first date
born 1990-03-15 — ISO date

Should not match

reference 12345 — Not a date
see page 42 — Not a date
not a date here — Plain prose

Known false positives

Non-DOB dates such as invoice dates, event dates, document timestamps, and meeting dates. Mitigation: Require birth-record keywords (DOB, date of birth, born) in proximity. Without these keywords the pattern fires at low confidence only.
Historical dates in news articles or academic papers that happen to match the date format. Mitigation: Corroborative evidence keywords distinguish personal records from historical references.
Dates in financial documents (settlement dates, maturity dates, filing dates). Mitigation: Filter excludes common business date labels via TextMatchFilter on the matched context.

References

https://learn.microsoft.com/en-us/answers/questions/2153006/microsoft-purview-custom-sit-date-of-birth
https://ico.org.uk/for-organisations/uk-gdpr-guidance-and-resources/personal-information-what-is-it/what-is-personal-data/