Currently the TimeZoneComparator class compares by time zone display name if the rawoffsets match. This causes a bug when there are two time zones which both have the same display name. The 'America/Denver' and 'US/Arizona' time zones both have the display name 'Mountain Standard Time', so when both are added to portal-ext.properties, only one will show because we use a TreeSet to store the time zones, and TreeSets don't allow duplicates.
Steps to reproduce:
1. Add the 'US/Arizona' time zone property along with all the other default time zone properties.
2. Navigate to My Account > Display Settings, and click the drop down.
There should be an Arizona time zone, and a Denver time zone (UTC -08:00 Mountain Standard Time and UTC -07:00 Mountain Daylight Time, respectively).
No time zone available for Arizona.
To test time zone changes:
1. Set user time zone in My Account > Display Settings to "Mountain Standard Time"
2. Add blog entry
3. Check time