iOS当前时间与另一个时间做比较

//endTime是要与当前时间做比较的另一个时间

- (void)keyLostTimeWithEndTime:(NSString *)endTime

{

    //当前时间

    NSDate* dat = [NSDate date];

    NSTimeInterval a = [dat timeIntervalSince1970]*1000;

    NSString *timeString = [NSString stringWithFormat:@"%f", a];

    long long nowTime = [timeString  longLongValue];

    long long end = [endTime longLongValue];

    //使用当前时间来判断还剩余多少天

    long long time = (end -nowTime)/1000/60/60/24;

    //获取当前时间戳

    if (end-nowTime >= 0) {

        if (time <= 1) {

            self.daysLbl.text = @"今日";

            self.daysDeatilsLbl.text = @"";

        }else{

            self.daysLbl.text = [NSString stringWithFormat:@"%ld天", (long)time];

            self.daysDeatilsLbl.text = @"距离";

        }

    }else if(end-nowTime < 0){

        long long time = (nowTime - end)/1000/60/60/24;

        if (time == 0) {

            self.daysLbl.text = @"今日";

            self.daysDeatilsLbl.text = @"";

        }else{

            self.daysLbl.text = [NSString stringWithFormat:@"%ld天", (long)time];

            self.daysDeatilsLbl.text = @"逾期";

        }

    }

}