1 function getYesterday(date) { 2   var date = date.split('-'), 3     today = new Date().setFullYear(+date[0], +date[1]-1, +date[2]),  //第二个参数减1因为月份是0~11 4     yesterday = new Date(today - 24 * 60 * 60 * 1000); 5        6   return '昨天是 ' + yesterday.getFullYear() + '-' + (yesterday.getMonth() + 1) + '-' + yesterday.getDate(); 7 } 8 alert(getYesterday('2012-1-1'));