How can I convert the following into a System.TimeZone or System.TimeZoneInfo?

```
{
  "timeZone": "America/Los_Angeles", 
  "currentOffsetMs": -25200000
}

```

This is data I'm getting back from a 3rd party web service.

I'm assuming the offset is the difference from UTC, and I'm told that the "America/Los\_Angeles" is an Olson time zone. Java has no problems parsing this into a Java TimeZone, but I need to parse this into a C# TimeZoneInfo object.