During testimony in the Tax Court of Canada on Thursday, Blackmore said he was directed by a patriarch in the community to get the money to "prepare for the worst."
The cash was to be used to gather supplies for the religious sect in southeast B.C., near the Canada-U.S. border, he said.
But it wasn't meant to be.
"Another deadline for the end of the world has come and gone. Some 15 deadlines have passed," Blackmore's self-published online newsletter later said in March 2004.
"Did you write that?" federal government lawyer Lynn Burch asked Blackmore.
"I could have wrote it," he said.
He acknowledged there had been at least 15 predictions for the end of the world from the prophet of the Fundamentalist Church of Jesus Christ of Latter-Day Saints, or FLDS.
"Perhaps many more," he added.
Burch asked if the predictions for the destruction of the world were part of the belief system of the FLDS faith, a splinter from the Mormon church.
"I don't think they're part of the tenet, but they certainly are part of the practice," he replied.
Blackmore is testifying as he fights allegations that he made an extra $1.5 million above what he claimed on his taxes from 2000 to 2004 and in 2006.
Mormons renounced polygamy more than a century ago, but Blackmore said he follows principles including plural marriage set out by church founder Joseph Smith.
Blackmore believes his income should be spread among residents in Bountiful, B.C., and that the group should be given special tax status similar to Hutterite colonies who have no property or possessions and work only for the community.
He also told the court that a "famine call" was issued shortly after the 2000 New Year.
"It was a time when everyone was pinching themselves," Blackmore said. "We were all happy the world had not ended."
He said the community saved for three months and sent tens of thousands of dollars to Rulon Jeffs, the then-church leader of the FLDS.
Burch asked if a famine call was basically a call for cash from the church leaders in the United States.
"Yes," he said.
"You're duty-bound to send cash," Burch said. "Obedience is an important tenet of your religious beliefs?"
"Yes," he replied.
Blackmore was a trustee for the United Effort Plan Trust before he was excommunicated by the FLDS in a dispute with the new leader Warren Jeffs.
The trust was formed in the 1940s by the FLDS in the United States so worshippers could turn over their assets. Men were then assigned land to build their homes from the trust. All property and buildings remained within the trust.
In 2005, the State of Utah stepped in to control the trust and suspended the trustees after allegations of breach of trust.
Blackmore filed a sworn affidavit for the Utah court in connection to the application, saying that no trustee ever voted independently on any trust matter and that they always deferred to the then-leader Rulon Jeffs, typically with no vote at all.
"You did it because you owed obedience to the president of the trust," Burch asked. "Were you afraid there could be ramifications?"
"It was not could have, it was would have," he replied
Burch asked if he worried for his family.
"My families as well as anyone else on that board could have our families removed from us the next day," he replied.
Blackmore said they could be kicked out of FLDS and their plural wives could be taken away and reassigned to someone else.
"It is in the power of the president to cause those consequences?" Burch asked.
"Yes," he replied.
The trial was expected to last for three weeks, but lawyers said Thursday it may not be completed by then and closing arguments may have to be heard at a later date and perhaps even at at different location.
Near the end of Blackmore's testimony Thursday, Judge Diane Campbell warned him to listen to the questions.
"There have been a number of times you haven't been paying attention," she scolded. "There have been times you've been unresponsive and have to be re-asked."
Blackmore finished his testimony and more witnesses will be heard Monday.
In earlier testimony, Blackmore admitted to having 22 wives and at least 67 children, although he said he couldn't give an accurate count of his children without looking at a list.