In 2017, the US star thought she was celebrating her 93rd birthday, but a birth certificate revealed that the actress was born on April 3, 1922, as Doris Mary Kappelhoff, and was 95 years old. "I've always said that age is just a number and I've never paid much attention to birthdays, but it's great to finally know how old I really am!" was Doris Day's reaction to the news.

After a car accident in 1937, the young Doris gave up her dreams of becoming a professional dancer and turned to singing instead. As a big-band singer, she took on the stage surname "Day" to replace the name given by her German ancestors, Kappelhoff. Her first hit recording, "Sentimental Journey," came out in early 1945 and became an anthem of the World War II troops hoping to return home.

Extremely successful in Les Brown's band, Day was the world's best paid female band vocalist by 1946. Her film debut came in 1948, with the role of a singer in "Romance on the High Seas." Her song "It's Magic" was nominated for an Oscar. She then starred in "I'll See You in My Dreams" (1951), which broke box-office records at the time.

In 1952, she co-starred in the biographical movie "The Winning Team" with an actor who'd later famously win something much bigger, becoming the 40th US President - Ronald Reagan. The film depicted the life of major league baseball pitcher Grover Cleveland Alexander (Reagan); Doris Day played the role of his wife, Aimee.

In the 1953 western musical "Calamity Jane," Doris Day starred as the title character (left in picture). The film was based on the life of the legendary Wild West heroine and her alleged love affair with Wild Bill Hickok (Howard Keel). It obtained an Academy Award for best original song, with the hit "Secret Love."

After demonstrating her talent in musical comedies, Day's breakthrough in more demanding, dramatic roles came with the biographical movie "Love Me or Leave Me" (1955), in which she co-starred with James Cagney. The film was based on the life of Ruth Etting, a Chicago nightclub singer who became a movie star. This was "her best film performance," Day later claimed in her autobiography.

A year later, she starred in Alfred Hitchcock's suspense thriller "The Man Who Knew Too Much" with James Stewart. In the film noir, Day also plays a popular singer, introducing her song "Que Sera, Sera (Whatever Will Be, Will Be)." It became a hit, obtained an Oscar for best original song and was used as her signature theme in her sitcom, "The Doris Day Show," at the end of the 1960s.

Her performance in the 1959 romantic comedy "Pillow Talk" earned Day an Oscar nomination for best actress, but she never won the coveted award. In the movie, she was an interior decorator who, despite initial feuds, falls in love with a womanizing bachelor, embodied by one of Hollywood's Golden Age heartthrobs, Rock Hudson. The actors co-starred in two more romantic comedies in the 1960s.

This picture is from one of Day's most iconic roles, as the mother of two young girls in the 1963 comedy "Move Over, Darling," co-starring James Gardner. The picture was originally planned to serve as Marilyn Monroe's comeback movie, under the title "Something's Got to Give," but the shoot was disrupted by her personal troubles and death in 1962.

When her third husband, Martin Melcher, died in 1968, Day was shocked to discover that he and his business partner had been wasting all of her money, leaving her bankrupt. He had also signed her without her knowledge to a television series, which she felt obliged to do. It became known as "The Doris Day Show," which ran from 1968-1973.

Another TV series, called "Doris Day's Best Friends" (1985-1986), focused on animals and their welfare. A life-long animal lover, Day founded the non-profit Doris Day Animal Foundation in 1978, which aims to rescue and protect animals. She also takes on lost animals in her home.

Now retired from acting and performing, Doris Day remains committed to promoting animal rights. She is pictured here at the Golden Globes in 1989, where she was given the Cecil B. DeMille Award for lifetime achievement. Her rich career would also justify her receiving the equivalent Academy Award, but that one hasn't come yet.