Kevin Mazur/WireImage; Axelle/Bauer-Griffin/FilmMagic Sarah Michelle Gellar celebrated 23 years of marriage with husband Freddie Prinze Jr. on Monday, Sept. 1, by posting a throwback wedding photo alongside a playful caption on Instagram TheI Know What You Did Last Summercostars wed in Mexico, in 2002 The couple share daughter Charlotte and son Rocky Sarah Michelle GellarandFreddie Prinze Jr.are celebrating 23 years of marriage, but who's counting? It turns out, theBuffy the Vampire Slayerstar is! The actress, 48, posted a playful tribute to her husband, 49, in honor of their 23rd wedding anniversary on Monday, Sept. 1. In a joint post onInstagram, she wrote, "23 years, 276 months, 1,196 weeks, 8,395 days, 201,480 hours, 12,088,800 minutes and 725,328,000 seconds give or take…. But who's counting ?!?" Gellar shared a throwback photo from the couple's 2002 wedding, which took place at the El Careyes resort in Mexico. In the photo, Prinze holds Gellar's hand as he helps her up a few of the venue's steps. The couple also matched in white for their big day. Initially, neither of theScooby-Doocostars "were into marriage," nor believed in it. However, their perspectives changed once their relationship became more serious. "One day, I just knew we were gonna get married and I knew I was gonna propose," Prinze toldPEOPLE Nowin 2020. "I didn't know when or how. And so I did and fortunately, she was on the same page. My instincts were correct." Gellar added, "I think for the first time it felt different right? Maybe it was the right time for both of us in our lives." Jerod Harris/Getty In 2000, theI Know What You Did Last Summercostars accidentally went on a first date after another friend canceled on dinner plans at the last minute, and the pair had instant chemistry. Less than two years after their friendship turned romantic, the couple got engaged in April 2001. Now, the couple sharestwo children: daughter Charlotte, born in 2010, and son Rocky, born in 2012. Never miss a story — sign up forPEOPLE's free daily newsletterto stay up-to-date on the best of what PEOPLE has to offer, from celebrity news to compelling human interest stories. Claire Greenway/Getty I Gellar credits her long-lasting marriage to them being mindful and present with each other. "Take the 10 minutes — put the phone down. Have a cup of coffee together. Walk the dog at the end of the night. Read a story with your kids,"she told PEOPLE in 2020. "Make the most of the time that you have. We are all pulled in so many directions, so make sure that, whichever one you are focusing on, you're present." Read the original article onPeople