Date

A date or time stamp. This is based on ISO 8601, but meant to allow for different degrees of precision by specifying a prefix. This means that 2021, 2021-02, 2021-02-16, 2021-02-16T21, 2021-02-16T21:48 and 2021-02-16T21:48:52 are all valid values, with an implied precision.