Mark your calendars.

E! News has learned exclusively that Spencer Pratt and Heidi Montag are set to tie the knot on Saturday, April 25, in an undisclosed location in Pasadena, Calif.

“This will be the real wedding,” says a source close to the couple, who last November staged a fake wedding for cameras in Mexico. “It’s being filmed as the season finale for The Hills.”

A rep for the couple declined comment.

E! News has learned that the controversial reality couple has already invited about 110 guests to the nuptials, but the list is expected to grow even larger as the wedding date nears. A source says the couple plans to wed in a sunset ceremony and is looking at a rooftop location for a reception.

Montag has already picked out her dress and, in fact, on at 3 p.m. on Thursday had her final fitting at the Monique Lhuillier boutique in Los Angeles.

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