In the expansion of `norm` to support mongodb that I'm developing, I've defaulted to only supporting `Time`. The `DateTime` type breaks things on so many levels, mostly because `DateTime()` generates a runtime error.
Fortunately, the `Time` function, though based on the traditional Unix timestamp (seconds from Jan 1, 1970), is signed and 64 bit. So, the actual time range is massive and includes time before 1970.
