Michael Douglas and Catherine Zeta-Jones shared birthday tributes to each other Saturday on Instagram. 

Zeta-Jones, 52, and Douglas, 77, share the same date of birth — Sept. 25. Douglas shared a throwback photo of the couple.

"My first night meeting Catherine at the Deauville Film Festival in 1998. I found out that she had the same birthday as me — tadaah!," Douglas wrote in his Instagram caption. "Then when I discovered she loved golf, I realized all my fantasies had come true. I've lucked out at this time in my life."

"I just lucked out. I'm so impressed by her intelligence, sense of humor and work ethic. Happy Birthday Catherine — I love you so much!"

EMMYS 2021 NOMINEE MICHAEL DOUGLAS ENJOYS DATE NIGHT WITH WIFE CATHERINE ZETA-JONES

Michael Douglas and Catherine Zeta-Jones wished each other a happy birthday in sweet Instagram tributes. They share the same birthday, Sept. 25. (Photo by Francis Specker/CBS via Getty Images)

Zeta-Jones shared her own post honoring Douglas.

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"Happy Birthday to me. Happy Birthday to him, Happy Birthday to my husband and his wife, Happy Birthday to me, and me, and me, and Michael," Zeta-Jones captioned her post.

"Here's to more years that we can celebrate September 25th together," she added. "Love you."

Zeta-Jones and Douglas tied the knot in 2000.

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The actress revealed the secret to their successful marriage is their strong connection in an interview with WSJ magazine.

"My husband and I spend a lot of time together because, unlike so many couples, we've never had a 9-to-5 job where it's consistent," she told the outlet. "We're either on or we're off. I'm really working 16 hours a day or I'm not. He's doing the same or not. So we've had in our relationship huge amounts of time where we've been just us."