If the request for entry of default was dated 8/25/2010, and proof of service is dated 7/16/2010.

How much time to I have to file a motion to set aside or to vacate?

How much time to I have to file a motion to set aside or to vacate?

To vacate what, the entry of default? Default judgment?

It would depend upon two things:

When was the thing you want set aside entered?
What court is it in (state, name of court)?

Entry of default, request to be entered was dated 8/25/2010

Orange County California Superior Court