if you're looking for interesting low-volume newsletters to subscribe to, i highly recommend the IANA timezone announcements mailing list.

two or three times per year, you get to learn interesting yet utterly useless facts such as "baja california didn't observe daylight savings up until 1952, used californian daylight savings rules in 1953, went back to using standard time year-round in 1954, observed DST again from 1961 through to 1975, then stopped entirely" and "the Asia/Choibalsan timezone is now synonymous with the Asia/Ulaanbaatar timezone due to, quote, 'wildly conflicting information about mongolia's timezone history'".