Yes, a version of TZDB is built into the NodaTime assembly, and is accessible via DateTimeProviders.Tzdb
. It's typically the version which was the latest at the time of the release build.
You can supply a newer version too, should you wish to (still without a network connection at execution time, because you'd take this step separately).
What doesn't exist at the moment (and it sounds like you don't need) is using an internet connection to fetch the latest version and use it at execution time.