Elsie Aslett thought she would receive her congratulatory 100th birthday telegram from the Queen on December 14th.
But pensions staff sent out to check the request uncovered her original birth certificate, which recorded the date as Dec 18 1908 - four days later than she had been told.
Relatives believe that her mother Elizabeth White, whom they described as "rather fond of her drink", may have confused dates between her eight children. She did not register Elsie's birth at Kennington Registry office in London until January 25 1909.
"It was all a bit of a surprise. You never doubt your date of birth. But it meant I could milk my celebrations for longer and draw them out for four days," she said. [Link]