Question

Is there any difference between using the Microsoft.VisualBasic.DateAndTime.Now compared to the System.DateTime.Now?

I seem to remember reading something that said the MS.VB namespace was for legacy use only, and was much slower than using the native .net classes.

Answer 1

There might be some cases, where using the VB namespace might be slower (because of the added functionality and/or flexibility, not because MS wants VB to be slower).

But in the case of DateAndTime.Now, this is not the case. This is simply a wrapper around a call to DateTime.Now.

I suspect the call to be inlined by the JIT-compiler, so it will not make your code any slower (when compile for Release).

Prove: This is the IL from DateAndTime.Now:

.method public specialname static valuetype [mscorlib]System.DateTime get_Now() cil managed
{
    .maxstack 1
    .locals init (
        [0] valuetype [mscorlib]System.DateTime time)
    L_0000: call valuetype [mscorlib]System.DateTime [mscorlib]System.DateTime::get_Now()
    L_0005: ret 
}

this is exactly the same as:

Return DateTime.Now