Example <html> <head> <title>JavaScript setDate Method</title> </head> <body> <script> var dt = new Date("December 30, 2017 11:20:25"); dt.setDate( dt.getDate() - 10 ); document.write( dt ); </script> </body> </html> Output Wed Dec 20 2017 11:20:25 GMT+0530 (India Standard Time)