<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">Doane lists the attached suggested resources for further research in her book — but does not provide a specific reference for each table item. <div class=""><br class=""></div><div class="">I’d be satisfied if software that relies on the tz database simply warned users that DST info prior to 1970 may not be correct.<div class=""><div><br class=""><blockquote type="cite" class=""><div class="">On Nov 23, 2018, at 3:45 PM, Paul Eggert <<a href="mailto:eggert@cs.ucla.edu" class="">eggert@cs.ucla.edu</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div class="">Jane Eisenstein wrote:<br class=""><blockquote type="cite" class="">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.<br class=""></blockquote><br class="">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.<br class=""><br class="">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.<br class=""><br class="">[1]<br class="">Shanks TG. The American Atlas. 5th ed. 1990. ACS. <a href="https://www.worldcat.org/title/american-atlas-us-longitudes-latitudes-time-changes-and-time-zones/oclc/468828649" class="">https://www.worldcat.org/title/american-atlas-us-longitudes-latitudes-time-changes-and-time-zones/oclc/468828649</a><br class=""></div></div></blockquote><br class=""><br class=""></div><img apple-inline="yes" id="F13AE121-5000-4F9D-80D6-E4B0D6D00AED" src="cid:A14EA511-9C21-47B1-BFDC-90C49C3DEFA5@fios-router.home" class=""></div></div></body></html>