While there are some religious institutions that hold services every day, many of the newer sects and branches have chosen to limit their religious gatherings for the entire congregation to once per week. These weekly services are a time when almost every member is present at some point during the day, and many have their favorite time to attend. Most meeting halls are not large enough to house the entire congregation at one time, so they usually schedule two or three services on the Sabbath.
Attending service at least once per week gives members an opportunity to see others on a regular basis, and it can give them a sense of structure in their life. Work is generally done during the weekdays, but most people have their weekends free. Attending church during that time gives them a definite destination, so it can help members divide up their free time to make it a positive experience.