[tz] Wisconsin daylight savings 1957
eggert at cs.ucla.edu
Sat Apr 17 16:47:38 UTC 2021
On 4/16/21 7:39 PM, TJ via tz wrote:
> In the tz db for North America, it looks like Wisconsin is using
> America/Chicago which has a few rules for the time period in question:
> Rule Chicago 1922 1954 - Sep lastSun 2:00 0 S
> Rule Chicago 1955 1966 - Oct lastSun 2:00 0 S
> It appears to me that Wisconsin might need some modification?
If the affected timestamps all predate 1970, we should be OK as far as
tzdb is concerned, as Wisconsin would still agree with America/Chicago
for timestamps after 1970.
Shanks divides Wisconsin into six distinct regions depending timestamp
histories before 1970. I expect that none of these histories agree with
Chicago's (and I also expect that Shanks' divisions are not completely
accurate, and that there may be more than six regions). Surely this
would be 'backzone' file material at best, though.
More information about the tz