# File lib/active_support/values/time_zone.rb, line 351 def [](arg) case arg when String begin lazy_zones_map[arg] ||= lookup(arg).tap { |tz| tz.utc_offset } rescue TZInfo::InvalidTimezoneIdentifier nil end when Numeric, ActiveSupport::Duration arg *= 3600 if arg.abs <= 13 all.find { |z| z.utc_offset == arg.to_i } else raise ArgumentError, "invalid argument to TimeZone[]: #{arg.inspect}" end end