ios 如何计算iOS中两个日期之间的时间（以小时为单位）

How to calculate time in hours between two dates in iOS

提问by iosrookie

How can I calculate the time elapsed in hours between two times (possibly occurring on different days) in iOS?

如何计算 iOS 中两次（可能发生在不同的日子）之间经过的时间（以小时为单位）？

回答by Akusete

The NSDatefunction timeIntervalSinceDate:will give you the difference of two dates in seconds.

该NSDate的功能timeIntervalSinceDate：给你两个日期的秒差。

 NSDate* date1 = someDate;
 NSDate* date2 = someOtherDate;
 NSTimeInterval distanceBetweenDates = [date1 timeIntervalSinceDate:date2];
 double secondsInAnHour = 3600;
 NSInteger hoursBetweenDates = distanceBetweenDates / secondsInAnHour;

See, the apple reference libraryhttp://developer.apple.com/library/mac/navigation/or if you are using Xcode just select help/documentationfrom the menu.

请参阅苹果参考库http://developer.apple.com/library/mac/navigation/或者如果您使用的是 Xcode，只需从菜单中选择帮助/文档。

See: how-to-convert-an-nstimeinterval-seconds-into-minutes

请参阅：how-to-convert-an-nstimeinterval-seconds-into-minutes

--edit: See D?r?D?vil's answer below for correctly handling daylight savings/leap seconds

--edit：请参阅下面的D?r?D?vil 的答案以正确处理夏令时/闰秒

回答by aahsanali

NSCalendar *c = [NSCalendar currentCalendar];
NSDate *d1 = [NSDate date];
NSDate *d2 = [NSDate dateWithTimeIntervalSince1970:1340323201];//2012-06-22
NSDateComponents *components = [c components:NSHourCalendarUnit fromDate:d2 toDate:d1 options:0];
NSInteger diff = components.minute;

NSDayCalendarUnit|NSHourCalendarUnit|NSMinuteCalendarUnit

Change needed components to day, hour or minute, which difference you want. If NSDayCalendarUnitis selected then it'll return the number of days between two dates similarly for NSHourCalendarUnitand NSMinuteCalendarUnit

将所需的组件更改为您想要的天、小时或分钟。如果NSDayCalendarUnit被选中，那么它将类似地返回两个日期之间的天数NSHourCalendarUnit和NSMinuteCalendarUnit

Swift 4 version

斯威夫特 4 版本

let cal = Calendar.current
let d1 = Date()
let d2 = Date.init(timeIntervalSince1970: 1524787200) // April 27, 2018 12:00:00 AM
let components = cal.dateComponents([.hour], from: d2, to: d1)
let diff = components.hour!

回答by Ashish Patel

-(NSMutableString*) timeLeftSinceDate: (NSDate *) dateT {

    NSMutableString *timeLeft = [[NSMutableString alloc]init];

    NSDate *today10am =[NSDate date];

    NSInteger seconds = [today10am timeIntervalSinceDate:dateT];

    NSInteger days = (int) (floor(seconds / (3600 * 24)));
    if(days) seconds -= days * 3600 * 24;

    NSInteger hours = (int) (floor(seconds / 3600));
    if(hours) seconds -= hours * 3600;

    NSInteger minutes = (int) (floor(seconds / 60));
    if(minutes) seconds -= minutes * 60;

    if(days) {
        [timeLeft appendString:[NSString stringWithFormat:@"%ld Days", (long)days*-1]];
    }

    if(hours) {
        [timeLeft appendString:[NSString stringWithFormat: @"%ld H", (long)hours*-1]];
    }

    if(minutes) {
        [timeLeft appendString: [NSString stringWithFormat: @"%ld M",(long)minutes*-1]];
    }

    if(seconds) {
        [timeLeft appendString:[NSString stringWithFormat: @"%lds", (long)seconds*-1]];
    }

    return timeLeft;
}

回答by Ankish Jain

Checkout : It takes care of daylight saving, leap year as it used iOS calendar to calculate. You can change the string and conditions to includes minutes with hours and days.

结帐：它使用 iOS 日历来计算夏令时，闰年。您可以将字符串和条件更改为包括分钟、小时和天。

+(NSString*)remaningTime:(NSDate*)startDate endDate:(NSDate*)endDate {

    NSDateComponents *components;
    NSInteger days;
    NSInteger hour;
    NSInteger minutes;
    NSString *durationString;

    components = [[NSCalendar currentCalendar] components: NSCalendarUnitDay|NSCalendarUnitHour|NSCalendarUnitMinute
                                                 fromDate: startDate toDate: endDate options: 0];
    days = [components day];
    hour = [components hour];
    minutes = [components minute];

    if (days > 0) {

        if (days > 1) {
            durationString = [NSString stringWithFormat:@"%d days", days];
        }
        else {
            durationString = [NSString stringWithFormat:@"%d day", days];
        }
        return durationString;
    }

    if (hour > 0) {

        if (hour > 1) {
            durationString = [NSString stringWithFormat:@"%d hours", hour];
        }
        else {
            durationString = [NSString stringWithFormat:@"%d hour", hour];
        }
        return durationString;
    }

    if (minutes > 0) {

        if (minutes > 1) {
            durationString = [NSString stringWithFormat:@"%d minutes", minutes];
        }
        else {
            durationString = [NSString stringWithFormat:@"%d minute", minutes];
        }
        return durationString;
    }

    return @"";
}

回答by john raja

For those who use swift 3 and above,

对于那些使用 swift 3 及以上版本的人，

    let dateString1 = "2018-03-15T14:20:00.000Z"
    let dateString2 = "2018-03-20T14:20:00.000Z"

    let Dateformatter = DateFormatter()
    Dateformatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ss.SSSZ"

    let date1 = Dateformatter.date(from: dateString1)
    let date2 = Dateformatter.date(from: dateString2)

    let distanceBetweenDates: TimeInterval? = date2?.timeIntervalSince(date1!)
    let secondsInAnHour: Double = 3600
    let secondsInDays: Double = 86400
    let secondsInWeek: Double = 604800

    let hoursBetweenDates = Int((distanceBetweenDates! / secondsInAnHour))
    let daysBetweenDates = Int((distanceBetweenDates! / secondsInDays))
    let weekBetweenDates = Int((distanceBetweenDates! / secondsInWeek))

    print(weekBetweenDates,"weeks")//0 weeks
    print(daysBetweenDates,"days")//5 days
    print(hoursBetweenDates,"hours")//120 hours