The Mormon Church is urging its faithful to remain calm, promising that Sunday's "blood moon" is not a sign that the end of days is upon us.

On Sunday, the moon will be full and closer to the Earth than at any other point in its orbit. Normally, that's just called a "supermoon" but in this case, the two events also happen to coincide with a lunar eclipse.

The sun's light, refracted around the Earth during the eclipse, will imbue the moon with a rusty hue, thus making it a "blood moon."

There have been four other blood moons since April 2014, but it's a typically rare confluence of events, and one that won't happen again for 18 years — if the Earth still exists then, which some Mormons and other doomsday preppers believe it won't.

This last blood moon, those people believe, marks the beginning of the end times. In the biblical book of Revelation, the moon turns red when the penultimate symbolic seal signaling Judgement Day is broken — "And I beheld when he had opened the sixth seal, and, lo, there was a great earthquake; and the sun became black as sackcloth of hair, and the moon became as blood."

Owners of Utah supply stores like Emergency Essentials and Thrive Life, which specializes in freeze-dried food, reported sales skyrocketing in recent months by 300 and 500 percent, respectively.

Leaders of the Church of Jesus Christ of Latter-day Saints released a message on Saturday that exhorted congregants to remain "spiritually and physically prepared for life's ups and downs," while urging them to "avoid being caught up in extreme efforts to anticipate catastrophic events."

Here's the church's full statement on the issue, via Salt Lake City's KUTV:

The Church encourages our members to be spiritually and physically prepared for life's ups and downs. For many decades, Church leaders have counseled members that, where possible, they should gradually build a supply of food, water and financial resources to ensure they are self-reliant during disasters and the normal hardships that are part of life, including illness, injury or unemployment.

This teaching to be self-reliant has been accompanied by the counsel of Church leaders to avoid being caught up in extreme efforts to anticipate catastrophic events.

The writings and speculations of individual Church members, some of which have gained currency recently, should be considered as personal accounts or positions that do not reflect Church doctrine.

The "individual" in question is Mormon author Julie Rowe, who claims to have seen visions of an impending apocalypse after a near-death experience in 2004. Earlier this month, the Church circulated a memo warning church teachers about Rowe's books.

In a statement she provided to The Salt Lake Tribune, Rowe said she hopes her readers prepare for the "times we live in by increasing their faith in Christ and by looking to our prophet and church leaders for guidance."