In the USA there is also a concept of night-VFR, and the FAA PPL includes this permission UNLESS specifically excluded (as it often is, for example, for a JAR licence holder without a night qualification using a reciprocal licence).
So far as I know, the only night/day VFR difference in the USA is that in class G whilst in the day the VFR minima are 1 statute mile 1000ft below, 500ft above, and 2000ft horizontally from cloud / clear of cloud below 1200AGL, at night for these minima to apply you must ALSO be in a traffic pattern, below 1200ft and within half a mile of a runway - otherwise a 3 statute mile visibility rule applies with the same cloud separation values.
G