Sarah Michelle Gellar and Freddie Prinze Jr. Celebrate 23rd Wedding Anniversary

Sarah Michelle Gellar and Freddie Prinze Jr. are celebrating 23 years of marriage, but who’s counting? It turns out, the Buffy the Vampire Slayer star 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 on Instagram, 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 the Scooby-Doo costars “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 told PEOPLE Now in 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.”

In 2000, the I Know What You Did Last Summer costars 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 shares two children: daughter Charlotte, born in 2010, and son Rocky, born in 2012.

Never miss a story — sign up for PEOPLE’s free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer, from celebrity news to compelling human interest stories.

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.”