iirc, according to past conversation on the mailing list, the reason why these timezones that are not in use for many years already still exists in tz database is because of legacy reason, however given that Asia/Ishigaki were deleted from this database in 1999 when it's found to be not in use, is there any reason preventing the same to be done to Asia/Harbin, Asia/Chongqing, and Asia/Kashgar?