$ zdump -v Asia/Hong_Kong | grep 1977
Asia/Hong_Kong Sat Apr 16 19:29:59 1977 UTC = Sun Apr 17 03:29:59 1977 HKT isdst=0 gmtoff=28800
Asia/Hong_Kong Sat Apr 16 19:30:00 1977 UTC = Sun Apr 17 04:30:00 1977 HKST isdst=1 gmtoff=32400
Asia/Hong_Kong Sat Oct 15 18:29:59 1977 UTC = Sun Oct 16 03:29:59 1977 HKST isdst=1 gmtoff=32400
Asia/Hong_Kong Sat Oct 15 18:30:00 1977 UTC = Sun Oct 16 02:30:00 1977 HKT isdst=0 gmtoff=28800
And, after upgrade to 2010m:
$ zdump -v Asia/Hong_Kong | grep 1977
Verify there is no output as DST was removed for 1977.
Test case for Hong Kong time zone change:
First, with 2010l:
$ zdump -v Asia/Hong_Kong | grep 1977
Asia/Hong_Kong Sat Apr 16 19:29:59 1977 UTC = Sun Apr 17 03:29:59 1977 HKT isdst=0 gmtoff=28800
Asia/Hong_Kong Sat Apr 16 19:30:00 1977 UTC = Sun Apr 17 04:30:00 1977 HKST isdst=1 gmtoff=32400
Asia/Hong_Kong Sat Oct 15 18:29:59 1977 UTC = Sun Oct 16 03:29:59 1977 HKST isdst=1 gmtoff=32400
Asia/Hong_Kong Sat Oct 15 18:30:00 1977 UTC = Sun Oct 16 02:30:00 1977 HKT isdst=0 gmtoff=28800
And, after upgrade to 2010m:
$ zdump -v Asia/Hong_Kong | grep 1977
Verify there is no output as DST was removed for 1977.