“Hallelujah!” exulted Ross Trewhella, a Mormon bishop in England, at news that The Church of Jesus Christ of Latter-day Saints was reducing its Sunday three-hour block of meetings to two hours.

Though widely rumored to be in the works, Saturday’s announcement at the beginning of the church’s 188th Semiannual General Conference about the shortened schedule took many in the 16 million-member faith by surprise.

After all, it marks the first major change to Latter-day Saints’ Sunday worship services since the three-hour block’s churchwide introduction in 1980.

Beginning in January 2019, a 60-minute sacrament service will be followed by a 50-minute class period after a 10-minute transition period.

Classes will alternate by week, with traditional Sunday school meetings on the first and third weeks of each month, and the faith’s all-male priesthood, female Relief Society and youth classes held on the second and fourth weeks.

In the event of a fifth Sunday in a given month, classes will be held at the discretion of local lay leaders. And Primary classes for young children will be held each week.

This change is meant to balance the roles of church and home in teaching Mormon principles, apostle Quentin L. Cook explained in his speech Saturday, “in a way that will greatly increase faith, spirituality, and deepen conversion to Heavenly Father and the Lord Jesus Christ.”

A shorter schedule, he said, allows more time for families to study the gospel at home on Sunday or at other times they choose. In connection with the changes, a new home-based study guide called “Come, Follow Me” will be distributed.

This will allow believers everywhere “to create a church program that works for them,” Trewhella wrote in an email. “Recognizing that everybody is different allows for individual adaptation about how best to learn and live the doctrines of the church.”

Speaking for Latter-day Saints in far-flung regions, the British bishop said the move will help “church leaders around the world reduce their burden for planning and executing church meetings. … These changes will have the biggest benefit in areas of the world where the church is smaller, by reducing the number of lessons that need to be taught every week.”

Utah writer and blogger Emily Jensen said the new schedule will work best for “those who have the church’s ideal family and home situation.”

She wonders, though, about those who are single, those “who consider their ward family, their family.”

In the past, Mormon authorities have discouraged members from creating small groups to study scripture. On Saturday, though, Cook suggested that approach as a way to address the problem of those who do not have homes where such supplemental worship can happen.

The apostle suggested that “young singles, single adults, single parents, part-member families, new members and others [could] gather in groups outside the normal Sunday worship services to enjoy gospel sociality and be strengthened by studying together the home-centered, church-supported resource.”

Kristine Haglund, former editor of Dialogue: A Journal of Mormon Thought and a single mom in Boston, said the new schedule might have “paradoxical effects on the Mormon community.”

On the one hand, it may “make it easier to reach out to neighbors and friends. Two hours of church is much more like what many Christians are used to. Inviting someone to church for three hours has always been a big ask,” she said. “I hope that this could meaningfully improve LDS outreach and interfaith activity.”

Like Jensen, Haglund worries about “those who don't have families at home with whom they can take advantage of the newly designed curricula emphasizing home study. There is likely to be a sense of loss, with fewer opportunities to connect with ward members in conversation over gospel topics.”

For such members, Haglund said, “an hour less communal study and worship, combined with the possibly less-regular visiting of the new ministering program, may further convince single members, or those in part-member or nontraditional households, that the church isn't really for them.”

Not all Latter-day Saints welcomed a reduction in worship time.

“Am I the only one sad about Sunday church going from three to two hours?” asked Mindi Glenn Ritzman of the Berkeley Ward, or congregation, in the Bay Area. “But I recognize that a lot of that might stem from attending a ward for the last 20 years where I heard many great insights in those three hours an overwhelming majority of the time.”

Historian Matt Bowman, author of “The Mormon People: The Making of an American Faith,” points to a time when members devoted even more time to church meetings.

The 1980 alteration to a three-hour Sunday block was prompted, at least in part, by the costs involved in traveling long distances to meetinghouses and the expense of keeping those churches open for a full Sabbath as well as during the week.

“The older Mormon worship system, with meetings strung throughout the week, presumed that Mormons lived in a tightknit community with an easily accessible chapel,” Bowman wrote in an email. “The three-hour block system sought to preserve that community by creating a quite long worship period on Sunday that incorporated those past weeknight activities and tried to keep that sense of comity alive.”

This latest shift, including its directives of “increased time and study with family, he said, “mirrors broader shifts within Mormonism.”

As the Utah-based faith becomes “larger and less geographically centralized, that older, vital Mormon community is increasingly being replaced with the family community,” Bowman said, a process evident in much else of what the church has been “emphasizing in its rhetoric about the family and gender over the past two decades.”

The shortened schedule also will be more energy efficient — as the church increasingly adopts more environmentally friendly building practices — by being able to house more congregations in a single meetinghouse so that their two-hour blocks don’t overlap, or by not needing churches open for as long.

Apostle David A. Bednar cautioned members not to “focus primarily upon the logistical aspects of what has been announced. We must not allow procedural details to obscure the overarching spiritual reasons these changes now are being made.”

The Sunday meeting schedule “was not simply shortened,” he said. “Rather, we now have increased opportunities and responsibilities as individuals and families to use our time for enhancing the Sabbath as a delight at home and at church.”

This move is the next step in a progression of making Mormonism work across the world.

In 1978, then-President Spencer W. Kimball instructed Latter-day Saints to stay in their home countries and build Zion where they live.

Two decades later, President Gordon B. Hinckley announced that the church would be constructing smaller (“mini”) temples, Bednar said, to bring “the sacred ordinances of the Lord’s house closer to Latter-day Saint individuals and families throughout the world.”

Further, the church has expanded its humanitarian efforts, the apostle said, introduced programs to help members afford education, and promoted training in self-reliance.

Top Latter-day Saint officials hope the move will increase faith “in the savior’s redeeming mission,” Bednar said. “Our only objectives are to facilitate continuing conversion to the Lord and to love more completely and serve more effectively our brothers and sisters.”