How to get a list of timezones in ruby?

with rails a simple way is:

ActiveSupport::TimeZone.all

If you want a ruby only solution, (rails independent) you can use the tzinfo gem.

require 'tzinfo'

TZInfo::Timezone.all_country_zone_identifiers
TZInfo::Timezone.all_country_zones
#...
#America/Chicago
#America/Indiana/Tell_City
#America/Indiana/Knox
#America/Menominee
#America/North_Dakota/Center
#America/North_Dakota/New_Salem
#America/North_Dakota/Beulah
#America/Denver
#America/Boise
#...