下面是Swift 3.0的一个实现，它使用Date扩展来获取最接近的小时数：

extension Date {
    func nearestHour() -> Date? {
        var components = NSCalendar.current.dateComponents([.minute], from: self)
        let minute = components.minute ?? 0
        components.minute = minute >= 30 ? 60 - minute : -minute
        return Calendar.current.date(byAdding: components, to: self)
    }
}

使用此方法

- (NSDate*) nextHourDate:(NSDate*)inDate{
    NSCalendar *calendar = [NSCalendar currentCalendar];
    NSDateComponents *comps = [calendar components: NSEraCalendarUnit|NSYearCalendarUnit| NSMonthCalendarUnit|NSDayCalendarUnit|NSHourCalendarUnit fromDate: inDate];
    [comps setHour: [comps hour]+1]; //NSDateComponents handles rolling over between days, months, years, etc
    return [calendar dateFromComponents:comps];
}

这将为您提供inDate的下一小时日期

func nextHourDate() -> NSDate? {
    let calendar = NSCalendar.currentCalendar()
    let date = NSDate()
    var minuteComponent = calendar.components(NSCalendarUnit.MinuteCalendarUnit, fromDate: date)
    let components = NSDateComponents()
    components.minute = 60 - minuteComponent.minute
    return calendar.dateByAddingComponents(components, toDate: date, options: nil)
}

由于以下几个原因，使用组件并不可靠：
1.不考虑秒数
1.添加秒时，很少会遗漏一秒
我在**Swift 4.***中找到的最可靠的方法是：

extension Date {
    func nearestHour() -> Date {
        return Date(timeIntervalSinceReferenceDate:
                (timeIntervalSinceReferenceDate / 3600.0).rounded(.toNearestOrEven) * 3600.0)
    }
}

使用下面的代码。它一定对你有帮助。

NSString *dateString=@"17:15";
    NSArray *strings = [dateString componentsSeparatedByString:@":"];

int firstPart=[[NSString stringWithFormat:@"%@",strings[0]] intValue];
int lastPart=[[NSString stringWithFormat:@"%@",strings[1]] intValue];

NSLog(@"LAST:%d",firstPart);

if (lastPart>0) {

    int output=firstPart+1;


    NSString *finalOutput=[NSString stringWithFormat:@"%d:00",output];

     NSLog(@"OUTPUT:%@",finalOutput);
}
else
{
     NSLog(@"OUTPUT:%@",dateString);
}

这是Swift 4/5版本-

func nextHourDate() -> Date? {
    let calendar = Calendar.current
    let date = Date()
    var minuteComponent = calendar.component(.minute, from: date)
    var components = DateComponents()
    components.minute = 60 - minuteComponent
    return calendar.date(byAdding: components, to: date)
}