There has been some controversy about the date of Beverly Sills's birthday. Although the year has never been in doubt (1929), sources have variously stated it as either May 25 or May 26. The major news media used May 25 for her obituaries and the Met used May 25 for its memorial tribute on Sept 16, 2007. Most reference books (Current Biography, Who's Who in America, etc.) also use the 25th. However, Sills's two autobiographies used May 26, which became the date used by some subsequent references, including several children's biographies and the Kennedy Center website. To make matters more confusing, Sills herself used both dates at different times in correspondence with fans and friends.
Sills's older brother Stanley Sills, helped clear up the controversy in a phone conversation on May 13, 2008, in which he related the following:
Sills's mother was old-fashioned about childbirth and did not want to have her children in hospitals. Both Stanley and his brother Sidney were born at home and their mother insisted on the same for Beverly. Shirley Silverman went into labor and had Beverly sometime before midnight on May 25. However, the doctor, who had been called once Shirley went into labor, did not get there until early morning on May 26. Beverly was already born and the doctor did not assist with the birth. He filled out the birth certificate with May 26 as the official date.
Shirley being the strong personality that she was, always insisted that Beverly was born on May 25 (joking that "I should know, I was there!") The family always celebrated Beverly's birthday on May 25.
Both days, in their own way, are correct.