[tz] Historical data for Iran

Michael H Deckers michael.h.deckers at googlemail.com
Thu Jun 2 14:55:33 UTC 2022

    I obviously have not stated my point clearly enough.

    The proposed text
          # ... but it is clear that standard time  in
          # Iran started on 1935-06-13 and not 1946.
    is incorrect.

    The decision to apply Tehran time in the
    government offices throughout the country was
    taken on 1935-06-13 (certainly not at midnight),
    so that it is by no means clear that it could
    have been applied on 1935-06-13 at 00:04:16
    in the whole country. It is also not clear
    that usage of UT + 03:30 in government
    offices implies its usage as standard time.

    While inclusion of incorrect statements
    into the comments does not affect the TZif
    files, it is bound to confuse contributors
    in the future, who may not have seen the
    current updates to Asia/Tehran and have
    to assume that sources for these incorrect
    statements exist.

    What really can be stated on the basis
    of the referenced document is that

       On 1935-06-13, UT + 03:30 was already
       in use as Tehran time, so that the
       switch from LMT to UT + 03:30 cannot
       have occurred as late as 1946 (as
       specified by Shanks & Pottenger).

    Michael Deckers.

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