because Unity 5.6(C# 2.0) dont has API TimeZoneInfo(C# 3.0) so import third-party lib: zoneinfo
http://www.codeplex.com/zoneinfo https://www.codeproject.com/Articles/25001/ZoneInfo-tz-Database-Olson-Database-NET-API https://en.wikipedia.org/wiki/Tz_database
tzdata-origin is origin data Assets/zoneinfo/Resources/tzdata is format-data ( remove uselss line )