Jane Eisenstein wrote:
I was born and raised in central Missouri and know most of Missouri did not observe daylight-savings time prior to 1967. Areas close to Kansas City or St. Louis did observe daylight-savings time prior to 1967. I’ve also attached supporting scans of Missouri daylight-savings time information from the 1991 revision of Time Changes in the U.S.A. by Doris Chase Doane.
Doane partitions Missouri into about two dozen regions with distinct time zone histories. In contrast, Shanks[1] lists 49 such regions in Missouri. Both authors say Missouri agrees with America/Chicago after 1970 so we haven't needed to create a new zone for any of these regions, under the guidelines Guy Harris mentioned. We've found Shanks to be unreliable, and if Doane (like Shanks) cites no sources it's probably no better than Shanks, and most likely worse. If someone did the legwork to come up with primary sources for Missouri (copies of old newspapers and the like), we could put the resulting data into the 'backzone' file. It'd be some work, though. [1] Shanks TG. The American Atlas. 5th ed. 1990. ACS. https://www.worldcat.org/title/american-atlas-us-longitudes-latitudes-time-c...