The 2017 Boston Marathon was the 121st running of the Boston Athletic Association's mass-participation marathon. It took place on Monday, April 17 (Patriots' Day in Massachusetts). Geoffrey Kirui won the men's race in 2:09:37 and Edna Kiplagat won the women's race in 2:21:52. Kathrine Switzer at age 70 ran the marathon under bib number 261, the same number she had worn 50 years previously in 1967, finishing in 4:44:31. That number was then retired from all future Boston Marathons. Women were not allowed to run marathons until 1972, but she registered under the name K. V. Switzer.