Probably, next year the same will occur in Ukraine. In other countries also there can be changes.
Inside processing occurs on Region/City. It is correct, as uses base of time zones from an operating system and does not demand additional updatings both Zend Framework, and XenForo.
I think that it is necessary to alter completely display to the user of time zones where from the phrase will be excluded UTC, and itself UTC will be in a separate field, automatically paying off depending on region. Or it will be necessary to form in the field of a choice of time zone a line otherwise, also automatically calculating UTC.