Reschedule Interview

You need to edit your title to say "Ask HN: Reschedule Interview?" to fit the style guide for asking questions.

As to your question (assuming you're a candidate): yes you can ask, but unless it's for a major reason outside your control (e.g. your doctor asks to change a medical appointment on top of your interview), generally it "brings you down a notch" in that it causes extra effort on their side (and makes you look slightly self-centered).