A Request for Comments specification that documents a standardized timestamp format for use in data interchange. This is a commonly accepted successor to the ISO 8601 standard.
An example of an RFC 3339 compliant timestamp is:
2022-09-14 10:45:17.345Z
RFC 3339 also allows the ISO 8601 format, which is identical except it requires a ‘T’ between the date and time elements, instead of the space allowed in RFC 3339.