On 2019-07-05 08:18, Chris Walton wrote:

On July 5, 2019 09:12 AM, Alois Treindl wrote:

...

https://data.iana.org/time-zones/ seems to contain only tzdata releases from 2016 upwards. I need to look into pre-2005 ones. Where can I find them? The reason is that I am checking New Brunswick, Canada DST in 1973. The zone America/Moncton was introduced in 2007, to be able to represent an unusual clock time of 0:01 for DST onset. America/Moncton does not list DST for 1973. That is the only year between 1945 and 2020 that NB would not have DST. Nearby zones like Halifax or St_Johns have 1973 DST, just like the rest of Canada? Is there a bug in America/Moncton ? Shanks has DST in 1973 for New Brunswick. According to the book “The Great Daylight Saving Time Controversy” by Chris Pearce (https://books.google.ca/books?isbn=1925516962), New Brunswick skipped daylight saving in 1973 after the province was hit by major flooding. $ zdump -Vc1972,1975 America/Moncton | awk -f zdump_trim.awk America/Moncton 1972 Apr 30 Sun 05:59:59 UT = 01:59:59 AST isdst=0 gmtoff=-14400 America/Moncton 1972 Apr 30 Sun 06:00:00 UT = 03:00:00 ADT isdst=1 gmtoff=-10800 America/Moncton 1972 Oct 29 Sun 04:59:59 UT = 01:59:59 ADT isdst=1 gmtoff=-10800 America/Moncton 1972 Oct 29 Sun 05:00:00 UT = 01:00:00 AST isdst=0 gmtoff=-14400 America/Moncton 1974 Apr 28 Sun 05:59:59 UT = 01:59:59 AST isdst=0 gmtoff=-14400 America/Moncton 1974 Apr 28 Sun 06:00:00 UT = 03:00:00 ADT isdst=1 gmtoff=-10800 America/Moncton 1974 Oct 27 Sun 04:59:59 UT = 01:59:59 ADT isdst=1 gmtoff=-10800 America/Moncton 1974 Oct 27 Sun 05:00:00 UT = 01:00:00 AST isdst=0 gmtoff=-14400

I attached cut down archive diffs with relevant changes to Moncton, which agree with all of the above. -- Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada This email may be disturbing to some readers as it contains too much technical detail. Reader discretion is advised.