Unable to use @index directive on DateTime fields

[Leigan0]

Related to 499

I have been unable to use @index directive on DateTime fields. When trying to set up indexes the library drops existing constraints (which I know how to avoid) but does not rebuild indexes on DateTime fields.

If this correct behaviour ?

Thanks

[michaeldgraham]

#608 I wanted to add this in my initial implementation, but was told not to. I will.