"Doris was up for a role when quite young and her age may have been miswritten on the audition form," her spokesman said
Credit: John Castro

Age is just a number — but sometimes it’s the wrong one.

Hollywood icon Doris Day was all set to celebrate her 93rd birthday on Monday until the Associated Press dug up her birth certificate and discovered her birth year was 1922, not 1924 as she long believed, revealing her to actually be turning 95.

“I’ve always said that age is just a number and I have never paid much attention to birthdays, but it’s great to finally know how old I really am!” the actress said in a statement Sunday.

But how did the legendary star’s age mix-up begin?

“There has long been speculation and rumors about Doris’ age and we get this question a lot, looks like we finally have the answer,” Day’s spokesman, Charley Cullen Walters, told the outlet. “The story I have heard the most is that at one point Doris was up for a role when quite young and her age may have been miswritten on the audition form. We don’t know if that’s correct, but if so it could’ve simply stuck for all these years.”

Credit: Courtesy of CW3PR

“Doris has never been one for celebrating her own birthday,” Walters previously told PEOPLE. “But she’s very excited to visit with friends and family throughout the day, certainly to spend time with her beloved animals, and now to see photos from all over the world via the #DorisBirthdayWish campaign, through which we hope to raise lots of attention and donations for her Doris Day Animal Foundation.”

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The actress is planning on spending her actual birthday with a low-key affair at her home in Carmel, California, but she has plenty of fans wishing her well thanks to a social-media campaign launched by the Doris Day Animal Foundation, which she founded in 1978 to rescue and protect animals. The campaign encourages pet owners to upload photos and videos to their favorite social-media platform with the hashtag #DorisBirthdayWish, and tag the Doris Day Animal Foundation (@ddaf_org).

“The #DorisBirthdayWish video and photo campaign has been a huge hit and Doris is thrilled that many people have made DDAF.org to go along with their entries,” Walters tells PEOPLE. “She has been loving viewing them throughout the weekend and will continue to do so through the birthday tomorrow so we hope as many people will submit and donate as possible!”

Doris Day
Credit: Photoshot/Getty

In honor of her birthday, the star and the foundation will choose the top 95 entries, which will be presented to the star as a special digital birthday card, and which will be featured on the DDAF website and on PEOPLE.com.

“We’ll show her the photos on her iPad, which she’ll review,” said her close friend Bob Bashara. “She loves seeing what the foundation is doing and hearing all the success stories of pets they have helped.”