下拉插件dropload js时间计算（几天前）

                        var dateDiff = function (timestamp) {
                            // 补全为13位
                            var arrTimestamp = (timestamp + '').split('');
                            for (var start = 0; start < 13; start++) {
                                if (!arrTimestamp[start]) {
                                    arrTimestamp[start] = '0';
                                }
                            }
                            timestamp = arrTimestamp.join('') * 1;
                            var minute = 1000 * 60;
                            var hour = minute * 60;
                            var day = hour * 24;
                            var halfamonth = day * 15;
                            var month = day * 30;
                            var now = new Date().getTime();
                            var diffValue = now - timestamp;
                            // 如果本地时间反而小于变量时间
                            if (diffValue < 0) {
                                return '不久前';
                            }
                            // 计算差异时间的量级
                            var monthC = diffValue / month;
                            var weekC = diffValue / (7 * day);
                            var dayC = diffValue / day;
                            var hourC = diffValue / hour;
                            var minC = diffValue / minute;
                            // 数值补0方法
                            var zero = function (value) {
                                if (value < 10) {
                                    return '0' + value;
                                }
                                return value;
                            };
                            // 使用
                            if (monthC > 12) {
                                // 超过1年，直接显示年月日
                                return (function () {
                                    var date = new Date(timestamp);
                                    return date.getFullYear() + '年' + zero(date.getMonth() + 1) + '月' + zero(date.getDate()) + '日';
                                })();
                            } else if (monthC >= 1) {
                                return parseInt(monthC) + "月前";
                            } else if (weekC >= 1) {
                                return parseInt(weekC) + "周前";
                            } else if (dayC >= 1) {
                                return parseInt(dayC) + "天前";
                            } else if (hourC >= 1) {
                                return parseInt(hourC) + "小时前";
                            } else if (minC >= 1) {
                                return parseInt(minC) + "分钟前";
                            }
                            return '刚刚';
                        };