Bounds Checking For Dates

[WillAyd]

The Hyper API establishes a date as a uint32, a time as a uint64 but I think writes both in as a int64

There are probably some weird edge cases when values cross the limits of int64 into uint64 so might want to do explicit bounds checking rather than the casts currently in code

[WillAyd]

The details of the OP aren't relevant in pantab 4.x, but the problem still remains