Oct 29, 2018

Checking for DST Calculations

To find out if your zoneinfo files are updated with the new calculations is to use the time zone dumper, zdump. For example, checking on Ubuntu when the pertinent DST time changes are in 2018:

$ zdump -v America/Toronto | grep 2018
America/Toronto  Sun Mar 11 06:59:59 2018 UTC = Sun Mar 11 01:59:59 2018 EST isdst=0 gmtoff=-18000
America/Toronto  Sun Mar 11 07:00:00 2018 UTC = Sun Mar 11 03:00:00 2018 EDT isdst=1 gmtoff=-14400
America/Toronto  Sun Nov  4 05:59:59 2018 UTC = Sun Nov  4 01:59:59 2018 EDT isdst=1 gmtoff=-14400
America/Toronto  Sun Nov  4 06:00:00 2018 UTC = Sun Nov  4 01:00:00 2018 EST isdst=0 gmtoff=-18000