NEW YORK — Autumn brings the end of beach weekends, boating and picnics and the resurgence of school, football … and church.

In an effort to refocus the attention of parishioners and possibly attract newcomers and the disaffected, many churches borrow a page from universities and designate a Sunday in September as a “homecoming.” Although the idea reaches back a couple of centuries for some parishes, it is taking on a more organized feel in the U.S. and Britain.

This year, the Christian communications organization Outreach Inc., based in Vista, Calif., started a campaign declaring Sunday (Sept. 13) as “Back to Church Sunday,” and offering a free toolkit that includes a “campaign planning guide,” promotional materials and a booklet entitled “Rethink Church.”

According to Outreach’s Web site, the campaign is “specifically designed to increase church attendance by empowering church members with the tools they need to welcome neighbors, friends, and loved ones back to church.”

In an interview, Outreach founder and CEO Scott Evans said the campaign was sparked by a recent study by Southern Baptist-affiliated Lifeway Research, which found that “82 percent of people who don’t go to church would be somewhat likely to go if invited, but that only 2 percent of people who do go to church had invited someone,” he said. Outreach, Evans said, wanted to provide a focus on “equipping people to be inviters.”

Eric Abel, the vice president of marketing for Outreach, said the organization works with about 17,000 churches; most of the interest in the back-to-church campaign is coming from evangelical or non-denominational churches.

According to Evans, there have been more than 1,000 requests for the tool kits. Outreach’s Web site allows people to record how many people they’ve invited to church; so far, the count is up to nearly 700,000.

In Great Britain, Back to Church Sunday, which this year is Sept. 27, was started in 2004 by the Anglican Diocese of Manchester. Anglican churches in New Zealand and Canada picked up the idea, and U.K. Baptist, Methodist and United Reform churches are also taking part.

While the U.S. “Back to Church Sunday” group is generating buzz on Facebook, many mainline Protestant churches were staging fall welcomes long before there was even electricity, much less computers. Concord Presbyterian Church in Statesville, N.C., is holding its 234th homecoming celebration on Sept. 20 — the congregation was founded in 1775 — with guest speakers and musicians.

Other churches are having outreach campaigns even though they’re not officially part of the Outreach effort. St. Peter’s Episcopal Church in Bennington, Vt., is asking each parishioner to invite a friend to church on Sept. 13 and is planning an outdoor Eucharist, a brunch and opportunities to inquire about various ministries. St. John’s Episcopal Church in Somerville, N.J., like many churches, registers Sunday School students at its welcoming Sunday, also Sept. 13.

One of the advantages of an organized campaign, according to both Evans and testimonials on the Church of England’s Web site, is that those who might hesitate or be embarrassed to issue an invitation could be encouraged by the fact that many others are doing it at the same time.

But does it work? A targeted outreach to the “unchurched” assumes two important things: one, that they want to be reached, and two, that they’re there to be reached at all. As it turns out, neither may be true.

In Britain, for example, where the Church of England hopes to attract some 500,000 new worshippers on Sept. 27, one fact sheet begins flatly, “The Church of England isn’t dead yet!” A 2007 study found that 26 million Britons are Christian (about half the total population), but only 5 million attend once a week, and two-thirds have “no connection” with a church.

“This secular majority presents a major challenge to churches,” the Churchgoing in the UK report said. “Most of them … are unreceptive and closed to attending church; churchgoing is simply not on their agenda.”

Closer to home, demographic shifts are battering U.S. churches, especially Catholic parishes. In the Diocese of Springfield, Mass., for example, there are simply fewer people to fill the pews. That’s led to two rounds of church closures, which have afflicted dioceses around the country. The Springfield diocese currently counts about 202,000 Catholics; that figure was three times as large 50 years ago.

Evans hopes the targeted outreach will help shed light on how to reach the unchurched — assuming they want to be reached. A likely follow-up survey, he said, would try to gauge results and ask, “How responsive were your people?”