js ?格式化时间毫秒

//格式华日期为2017-12-20 ???function datefomate(value) { ???????if(value==null || value == undefined){ ???????????return ""; ???????} ???????var date = new Date(value); ???????????????Y = date.getFullYear(), ???????????m = date.getMonth()+1, ???????????d = date.getDate(), ???????????H = date.getHours(), ???????????i = date.getMinutes(), ???????????s = date.getSeconds(); ???????return Y+‘-‘+m+‘-‘+d; ???};