NodaTime 

Noda Time is a date and time API acting as an alternative to the built-in DateTime/DateTimeOffset etc types in .NET.

Provides serialization support between Noda Time and Json.NET.

Provides extra types which may be useful when testing code which uses Noda Time, such as a fake programmable implementation of IClock and a time zone which has a fixed transition. These types are also used to test Noda Time itself.

Provides serialization support between Noda Time and Google.Protobuf