Instead, refer to XML Schema's xsd:dateTime production rules directly, and refer to RFC 3339 and RFC 9557 as well for clarifying common confusions.
Omitting seconds is a questionable "feature" that creates more problems than it solves. I'm not sure what problems it solves vs just using :00, but it breaks compatibility with every RFC 3339 compliant datetime library, which is a very heavy ecosystem cost if it means every AS2 processor has to write their own bespoke datetime library (or monkey-patch an existing one) to account for as2-partial-time.
Instead, refer to XML Schema's xsd:dateTime production rules directly, and refer to RFC 3339 and RFC 9557 as well for clarifying common confusions.
Omitting seconds is a questionable "feature" that creates more problems than it solves. I'm not sure what problems it solves vs just using :00, but it breaks compatibility with every RFC 3339 compliant datetime library, which is a very heavy ecosystem cost if it means every AS2 processor has to write their own bespoke datetime library (or monkey-patch an existing one) to account for as2-partial-time.