Problem
In the time zone settings list, only few limited countries and time zones are available. Need to add other countries as well.
Solution
Have added the remaining countries as well as part of the time zones. This changes is done for UI and cli.

Tested that the remaining countries are displayed as part of the UI and cli when user selects the respective continent, country and time zone
AN(config)#system timezone 
Select the continent (Enter the corresponding number or 0 to exit):

  1.   Asia

  2.   Europe

  3.   North America

  4.   Oceania

  5.   Africa
time-zone-shell> 2
Select the country/region (Enter the corresponding number or 0 to move up one level):

  1.   Austria

  2.   Belgium

  3.   Denmark

  4.   France

  5.   Finland

  6.   Germany

  7.   Greece

  8.   Hungary

  9.   Israel

 10.   Italy

 11.   Ukraine

 12.   Russia

 13.   Netherland

 14.   Norway

 15.   Spain

 16.   Sweden

 17.   Switzerland

 18.   United Kingdom

 19.   Portugal

 20.   Turkey
time-zone-shell> 3
Select the time zone (Enter the corresponding number or 0 to move up one level):

  1.   Denmark