Back in 2011, just after the release of her fourth album, 4, Beyoncé told W magazine how the number four had achieved such a place of significance in her life: "Four is my favorite number. It's an important number in my life: the date of my birthday, my mom's birthday, my husband's birthday, the day I got married. Barack Obama is the 44th president, and I performed 'At Last' by Etta James at his inauguration."

Tuesday (September 4), Bey (with her legions of fans) can celebrate the number four once again for good reason — it's her 37th birthday. And on Twitter, her mother, Tina Knowles, made sure to kick things off with a very cute, heartfelt baby photo and a greeting on her daughter's day.

"Happy Birthday to the nicest, owner of the most beautiful, generous, loving hearts ever," she wrote in the caption. "Brilliant too! Always thinking, planning, analyzing, strategizing, how you can make everything you touch better! On this day you were 4 months old and I couldn't even control the excitement and pride and the all encompassing love I felt for you, my first born."

Last summer, Beyoncé welcomed two new additions to her family in twins Sir and Rumi, with her husband, Jay-Z. And just last month, she was featured as the cover star for Vogue's September issue, shot by 23-year-old Tyler Mitchell, whom Bey hand-picked — making him the first-ever African-American photographer to shoot a cover in the fashion magazine's 126-year history.

In that interview, Bey details her road to giving birth and the challenges she faced both before and after Sir and Rumi arrived. "I was 218 pounds the day I gave birth to Rumi and Sir," she revealed. "I was swollen from toxemia and had been on bed rest for over a month. My health and my babies' health were in danger, so I had an emergency C-section. We spent many weeks in the NICU. My husband was a soldier and such a strong support system for me. I am proud to have been a witness to his strength and evolution as a man, a best friend, and a father. I was in survival mode and did not grasp it all until months later."

Bey and Jay are currently trekking around the globe on their joint On the Run II tour, which culminates in Seattle a month from now. They also dropped a collaborative album, Everything Is Love, in June.

In other words, she's been busy. Here's hoping she can enjoy the fourth day of the month as it is, after all, her day.