On Thu, 2 Mar 2023 at 17:45, Paul Eggert via tz <
tz@iana.org> wrote:
Whether the adjusted time in (say) New York would be abbreviated "EST"
or "AST" or "EDT" is up to common practice.
[…]
At some point "EST" might become the
best of the alternatives.
Worth considering that, if "EST" were to become standard for -04, it would require modifications to supported, but obsoleted, formats in RFC 2822 §4.3, which state:
EDT is semantically equivalent to -0400
EST is semantically equivalent to -0500
CDT is semantically equivalent to -0500
CST is semantically equivalent to -0600
MDT is semantically equivalent to -0600
MST is semantically equivalent to -0700
PDT is semantically equivalent to -0700
PST is semantically equivalent to -0800