Aus den folgenden Links geht Folgendes hervor:

1) Die "evening social hours" finden vor dem Abendessen statt
2) Sie dienen der Begegnung. Das ist das Entscheidende
3) Meist werden Getränke und leichte Snacks gereicht, es gibt aber kein besonderes Programm

In Frankreich hat der Apéritif diese Funktion. Es ist schwer, einen deutschen Begriff zu finden, der dies alles umfasst. "Gemütliches Beisammensein", "Zeit der Begegnung" usw. klingt etwas komisch, "Empfang" ist zu steif.

Our popular evening social hour, held daily at the St Francis Inn from 5:30-6:30, offers guests a chance to meet fellow guests in a casual, comfortable setting. For your pleasure, we serve complimentary beverages and tasty treats on a four-day rotation schedule.
http://our-beach.com/menus.html

Our evening social hour (Mon-Thurs;5:30pm-7:30pm)offers a light dinner with beer and wine service.
http://jobs.hospitalityonline.com/120880/

Back in 1981, Bill Kimpton personally supervised every aspect of each guest's stay in his hotel. He made sure Kimpton beds were comfortable, the water pressure was strong, the lobby was sparkling, and the employees were friendly. And he made a point of greeting each guest personally at the hotel's Hosted Evening Wine Hour. Today, all of our hotels continue to honor this tradition, with a social hour, hosted by the General Manager. This is a relaxing opportunity for guests to mingle with each other, and taste unique wines from around the world. We're still the only hotel company that offers guests this quality time at the end of each day.
http://www.kimptonhotels.com/services/wine-hour.aspx