Hello, Generated timezone files using the below command on release 2018e. zic -L /dev/null -d output_dir -y "sh yearistype.sh" europe zdump show daylight saving flag (isdst=1) is wrongly set for Europe/Dublin. Daylight saving time should start from March 31 and end on October 27. But here it shows reverse. zdump -v /home/basavaia/output_dir/Europe/Dublin | grep 2019 /home/basavaia/output_dir/Europe/Dublin Sun Mar 31 00:59:59 2019 UT = Sun Mar 31 00:59:59 2019 GMT isdst=1 gmtoff=0 /home/basavaia/output_dir/Europe/Dublin Sun Mar 31 01:00:00 2019 UT = Sun Mar 31 02:00:00 2019 IST isdst=0 gmtoff=3600 /home/basavaia/output_dir/Europe/Dublin Sun Oct 27 00:59:59 2019 UT = Sun Oct 27 01:59:59 2019 IST isdst=0 gmtoff=3600 /home/basavaia/output_dir/Europe/Dublin Sun Oct 27 01:00:00 2019 UT = Sun Oct 27 01:00:00 2019 GMT isdst=1 gmtoff=0 Above Behavior is same in 2019a also. If I check the same on 2018a, it gives proper output. zdump -v /home/basavaia/2018a/Europe/Dublin | grep 2019 /home/basavaia/2018a/Europe/Dublin Sun Mar 31 00:59:59 2019 UT = Sun Mar 31 00:59:59 2019 GMT isdst=0 gmtoff=0 /home/basavaia/2018a/Europe/Dublin Sun Mar 31 01:00:00 2019 UT = Sun Mar 31 02:00:00 2019 IST isdst=1 gmtoff=3600 /home/basavaia/2018a/Europe/Dublin Sun Oct 27 00:59:59 2019 UT = Sun Oct 27 01:59:59 2019 IST isdst=1 gmtoff=3600 /home/basavaia/2018a/Europe/Dublin Sun Oct 27 01:00:00 2019 UT = Sun Oct 27 01:00:00 2019 GMT isdst=0 gmtoff=0 Is my understanding correct? And this behavior is introduced in commit 127b4af7219e6df9253b34e390797c5527b8cc66 I am not in this mailing list, please include my email id while responding. -- Guruswamy Basavaiah