module TimeZoneTestHelpers def with_tz_default(tz = nil) old_tz = Time.zone Time.zone = tz yield ensure Time.zone = old_tz end def with_env_tz(new_tz = "US/Eastern") old_tz, ENV["TZ"] = ENV["TZ"], new_tz yield ensure old_tz ? ENV["TZ"] = old_tz : ENV.delete("TZ") end def with_preserve_timezone(value) old_preserve_tz = ActiveSupport.to_time_preserves_timezone ActiveSupport.to_time_preserves_timezone = value yield ensure ActiveSupport.to_time_preserves_timezone = old_preserve_tz end end