Error in regexp for dateOfBirth validation

[ypiguet-epfl]

The regexp suggested to validate dateOfBirth, vaccinationDate, and dateOfFirstPositiveTestResult, has at least 3 errors:

• The first character set [19|20] should be a parenthesized alternative (19|20). It actually accepts a valid year because the regexp doesn't begin with a boundary ^, but it doesn't reject "0000-01-01", "not born on 1980-01-01", or "|99-01-01".
• It rejects day 10 and 20. E.g. in JavaScript. /[19|20][0-9][0-9]-(0[1-9]|1[0-2])-([0-2][1-9]|3[0|1])/.test("1980-10-20") is false instead of true.
• The last character set should not include the pipe: /[19|20][0-9][0-9]-(0[1-9]|1[0-2])-([0-2][1-9]|3[0|1])/.test("1980-10-3|") is true instead of false.

Suggestion: Use the following regexp: "^(19|20)[0-9][0-9]-(0[1-9]|1[0-2])-(0[1-9]|[1-2][0-9]|30|31)$".

[fabianegli]

Regex is not the right tool to validate date inputs. Some calendar/date utility should be used instead.

A simple regex will fail for example for leap days: "2020-02-29" is a valid date but "2021-02-29" is not.

A real leap day: should be true

> /^(19|20)[0-9][0-9]-(0[1-9]|1[0-2])-(0[1-9]|[1-2][0-9]|30|31)$/.test("2020-02-29")
true

Not a real date: should be false

> /^(19|20)[0-9][0-9]-(0[1-9]|1[0-2])-(0[1-9]|[1-2][0-9]|30|31)$/.test("2021-02-29")
true

[delixfe]

This regex is not used for validation. We will remove it from the documentation. Dates and DateTimes must follow ISO 8601.

[delixfe]

@ypiguet-epfl Thanks again for raising the issue. I have updated the documentation.