When can we neglect the effect of diode capacitance?

I was told that for DC and low-frequency AC circuits, the effect of diode capacitance can be neglected. The model of the diode of concern here is that which represents the diode as a current source with a capacitor in parallel.

I’m unable to see why this is a reasonable approximation in the DC and low frequency AC cases (and not in other cases). Could someone please explain the details? Thanks!