vittorius

class Time
  TZ_ABBREVIATION_MAP = ActiveSupport::TimeZone.all.each_with_object({}) do |tz, hash|
    [tz.tzinfo.current_period.start_transition, tz.tzinfo.current_period.end_transition].each do |transition|
      hash.merge!(transition.offset.abbreviation.to_s => tz.tzinfo.name) if transition.present?
    end
  end.merge('UTC' => 'Etc/UTC').freeze

  class << self
    def tz_name_for(time_like)
      TZ_ABBREVIATION_MAP[time_like.zone]