I have started reviewing pre-1970 US timezone history. The information is so complex that it is best approached state by state. I have started alphabetically with Alabama, but will probably continue with some mixture like - most populous states first - simplest states first For Alabama history my first draft proposes ten zones. This is more detailed than Shanks, wo distinguished seven areas. It is only a first step. Newspaper archive research (sadly) reveals that there are far more complex details involved in a complete history, and many questions about extension of zones can probably never be answered because there are not enough precise records. I have made a map, together with the help of colleagues, and uploaded it to wikimedia, as I am not sure whether image files work in this mailing list. Certainly we save bandwidth, as in the old times. License question: For now I have decided to place my work under the widest possible Creative Commons. This differs from the Public Domain license only in so far, as sources need to be quoted. Aside of that the use of the information is free, also within commercial projects of any kind. Please check and proof read the proposed zones. I am a bad typist.