DateFormat

This trait indicates that a String value contains a date without a time component. Following the RFC-3339 (an extension of ISO 8601), the default for a date is the following: date-fullyear = 4DIGIT date-month = 2DIGIT ; 01-12 date-mday = 2DIGIT ; 01-28, 01-29, 01-30, 01-31 based on ; month/year full-date = date-fullyear "-" date-month "-" date-mday

See: https://www.rfc-editor.org/rfc/rfc3339#section-5.6 e.g.: "2022-03-30" If a time component is required, you can use smithy.api#Timestamp