John Mayer disses Taylor Swift on her birthday nickiswift.com

John Mayer may still have hard feelings for Taylor Swift. The "Love on the Weekend" singer posted a shady tweet on her birthday. John Mayer may still have hard feelings for Taylor Swift. On Dec. 13, 2016—Swift's 27th birthday—the "Love on the Weekend" singer tweeted, "Tuesday, December 13 may be the lamest day of the year, conceptually."