An afterhours club (aka after hours club and afterhour club) in North America and Europe is a nightclub that is open past the designated curfew closing time for clubs that serve alcohol (which is often an hour long). Such clubs may cease serving alcohol at the designated time, but have special permission to remain open to customers and to sell non-alcoholic sodas and (typically) high-caffeine drinks.
More recently (since 2000), in Western Europe - specifically in Germany, Spain and the United Kingdom, 24 Hour "music and dance" licences have been granted and which do not necessarily have alcohol restrictions.
In North America, after hours clubs are venues, typically small, for (i) professional musicians and entertainers to perform after their main gigs and (ii) patrons seeking entertainment after the theater and such.
Europe
Historic Europe
North America
Historic North America