The 12 well-known US time zones have been dropped from Debian tzdata as
These time zones are still officially recognized and fully supported by
IANA Timezone Database:
Their removal appears to be related to this request:
This request does not provide any support as to why Debian should
deviate from IANA standards.
Requesting that Debian again adopt international time zone standards and
support these well known IANA time zones as it does in Bookworm.