function getBeforeDate(n){ var n = n; var d = new Date(); // var year = d.getFullYear(); var mon=d.getMonth()+1; var day=d.getDate(); if(day <= n){ if(mon>1) { mon=mon-1; } else { year = year-1; mon = 12; } } d.setDate(d.getDate()-n); year = d.getFullYear(); mon=d.getMonth()+1; day=d.getDate(); s ='' +""); return s; } var a=$("#a").html(getBeforeDate(-7));