The movement has elicited skepticism and outright ridicule from some quarters, but it has momentum. The local gathering is one of many Sunday Assembly startups expected to launch that same day, bringing the total number of chapters across the globe to an anticipated 100 or so by the end of the year.

“It’s fellowship without the dogma,” said Lavada Luening of West Allis, organizer of Sunday Assembly Milwaukee, which started in December. It has only a handful of core members, she said, but hasn’t done much publicity and is still building its infrastructure. The Madison founders said they don’t know how many participants to anticipate initially.

The first-ever Sunday Assembly was held about 18 months ago in London, launched by two British comedians, Sanderson Jones and Pippa Evans. In a guest column in the New York Times, the two said they started Sunday Assembly “because the idea of meeting once a month to sing songs, hear great speakers and celebrate the incredible gift of life seems like a fun, and useful, thing to do.”