"regular gathering" is correct and usable in written English.
You can use it to refer to an event or activity that happens on a regular basis. For example: "Our family has a regular gathering every Sunday night for dinner."
On Friday night, about 60 or 70 individuals gathered in Manchester's Veteran's Memorial Park — a regular gathering place for the protesters here.
Robert Brozon had just missed his friends, a regular gathering of social workers.
For the contributors, many of whom flew here from across the country, it was a regular gathering.
In January he created a "Sunday Assembly"—a regular gathering for non-religious Londoners featuring storytelling, jokes and singing to a live band.
How do we make something of all this?' " said Adriana Sá, a musician and composer who had begun holding the regular gathering, called Sabaduo, a week earlier.
And Promen (groups.yahoo.com/group/promen), a network of gay professionals, is holding its regular gathering downtown at the extravagant Lan Club (+10 5109 6012/13, lanbeijing.com).
These salons were regular gatherings hosted by prominent aristocratic women, where women and men could gather together to discuss the issues of the day.
I wish to bow out of the regular gatherings but remain friends.
Indonesian Atheists was founded with a Facebook page in 2008 and now holds regular gatherings.
Historically, the English may be credited with the evolution of Parliament, which, in its medieval form, was related to the Anglo-Saxon practice of regular gatherings of notables.
He is unlikely to give up his objective of holding more regular gatherings but can expect less support from national leaders.
