Kino Douglas, 31, who describes himself as agnostic, said his sister, Stacey, 33, is one of those who believe good Christians will be called to heaven Saturday while non-believers will be left to perish over the course of the next five months, The New York Times reported Friday.
Douglas said his sister "doesn't want to talk about anything else."
"I'll say, 'Oh, what are we going to do this summer?' She's going to say, 'The world is going to end on May 21, so I don't know why you're planning for summer,' and then everyone goes, 'Oh, boy,'" he said.
Grace Haddad, 16, said her parents brought her and her two siblings from Maryland to New York to help spread the word of the upcoming end times.
"My mom has told me directly that I'm not going to get into heaven," she said. "At first it was really upsetting, but it's what she honestly believes."
May 21 was proclaimed judgment day by Harold Camping, a co-founder and host for the California-based Family Radio network. He previously predicted the end times would arrived in 1994, but later said he had made an error in his math.
The Mayan calendar puts the end of the world at Dec. 21, 2012.