How to: make changes to a var over real time units instead of frame units? Mathf.Lerp

The following changes the variable myVar each frame, but how do I change it every certain number of milliseconds? Let's say every .1 seconds.

Mathf.Lerp(myVar, 0.0f, 0.5f)

Use InvokeRepeating:

var myVar : float;

function Start () {
    InvokeRepeating("LerpVar", .1, .1);
}

function LerpVar {
    myVar = Mathf.Lerp(myVar, 0.0, someIncrement);
}