I see the problem now. When I originally wrote the library, there were not nullable types supported in either C# or VB.NET. The native library uses strings that can have the following values:
- 'null' == 'Never delete'
- 'PT0S' (or TimeSpan.Zero) == 'Immediately'
-
'PTxx' == other times
- TimeSpan.Zero == 'Never delete'
- TimeSpan.FromSeconds(1) == 'Immediately'
-
TimeSpan (other) == other times