Problems with Date (only windows?)

After having some problems with a Date in my application, I discovered something that I consider very serious: There is no error raised when entering absurd values:

d.day = 300 d.month = 120 d.year = -100
produces 1601-10-27
At least on Windows, because when I tried to enter a Feedback case I found that there are a lot about it:

feedback://showreport?report_id=11397
feedback://showreport?report_id=11568
feedback://showreport?report_id=19687
etc.

And they state that behaviour is not equal on Windows and OSX.

All these cases and others are about more than three years old.
I suppose that Xojo.Core.Date must have solved all these problems. At least practically all properties are Read-Only ones. So previous code won’t be allowed.
If we must assume that Xojo is not going to solve all these bugs because there is a new framework, at least they should modify the LR, warning users about operating with date properties.