How to compare time

Question

How to compare time in Objective C?

if (nowTime > 9:00 PM) && (nowTime < 7:00 AM) 
{
  doSomething;
}

Answer 1

I used the Answer Given above by rye. I just had to convert my 7:00 AM and 9:00 PM to 24 hours. Here's the method I used

/**
Willl return YES if the Restaurant is OPEN at the Moment else NO
*/


-(BOOL) isShopOpen:(NSString *) startTime closeTime:(NSString *) endTime{

NSDateComponents *components = [[NSCalendar currentCalendar] components:NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit fromDate:[NSDate date]];
NSInteger currHr = [components hour];
NSInteger currtMin = [components minute];

int stHr ;
int stMin ;
int enHr ;
int enMin ;


if([startTime containsString:@"PM"]){
    startTime = [startTime stringByReplacingOccurrencesOfString:@" PM" withString:@""];

    stHr=[[[startTime componentsSeparatedByString:@":"] objectAtIndex:0] intValue];
    stHr=stHr+12;

    stMin = [[[startTime componentsSeparatedByString:@":"] objectAtIndex:1] intValue];

}else{
    startTime = [startTime stringByReplacingOccurrencesOfString:@" AM" withString:@""];

    stHr=[[[startTime componentsSeparatedByString:@":"] objectAtIndex:0] intValue];
    stMin = [[[startTime componentsSeparatedByString:@":"] objectAtIndex:1] intValue];
}

if([endTime containsString:@"PM"]){
    endTime = [endTime stringByReplacingOccurrencesOfString:@" PM" withString:@""];

    enHr=[[[endTime componentsSeparatedByString:@":"] objectAtIndex:0] intValue];
    enHr=enHr+12;

    enMin = [[[startTime componentsSeparatedByString:@":"] objectAtIndex:1] intValue];

}else{
    endTime = [endTime stringByReplacingOccurrencesOfString:@" AM" withString:@""];

    enHr=[[[endTime componentsSeparatedByString:@":"] objectAtIndex:0] intValue];
    enMin = [[[startTime componentsSeparatedByString:@":"] objectAtIndex:1] intValue];
}

int formStTime = (stHr*60)+stMin;
int formEnTime = (enHr*60)+enMin;

int nowTime = (currHr*60)+currtMin;

if(nowTime >= formStTime && nowTime <= formEnTime) {
    // Do Some Nasty Stuff..
    return YES;
}else{
    return NO;
}

}

Answer 2

If you want to get the current hour and compare it to some times, you're going to have to use NSDate, NSDateComponents, and NSCalendar.

NSDateComponents *components = [[NSCalendar currentCalendar] components:NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit fromDate:[NSDate date]];
NSInteger currentHour = [components hour];
NSInteger currentMinute = [components minute];
NSInteger currentSecond = [components second];

if (currentHour < 7 || (currentHour > 21 || currentHour == 21 && (currentMinute > 0 || currentSecond > 0))) {
    // Do Something
}

That will check if the time is between 9:00 PM and 7:00 AM. Of course, if you're going to want different times you'll have to change the code a little.

---

Read about NSDate, NSDateComponents, and NSCalendar to learn more.

Answer 3

Theres a perfect formula for this. Just for future references

Below is the sample code :

NSDateComponents *components = [[NSCalendar currentCalendar] components:NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit fromDate:[NSDate date]];
NSInteger currHr = [components hour];
NSInteger currtMin = [components minute];

NSString *startTime = @"21:00";
NSString *endTime = @"07:00";

int stHr = [[[startTime componentsSeparatedByString:@":"] objectAtIndex:0] intValue];
int stMin = [[[startTime componentsSeparatedByString:@":"] objectAtIndex:1] intValue];
int enHr = [[[endTime componentsSeparatedByString:@":"] objectAtIndex:0] intValue];
int enMin = [[[endTime componentsSeparatedByString:@":"] objectAtIndex:1] intValue];

int formStTime = (stHr*60)+stMin;
int formEnTime = (enHr*60)+enMin;

int nowTime = (int)((currHr*60)+currtMin);

if(nowTime >= formStTime && nowTime <= formEnTime) {
    // Do Some Nasty Stuff..
}

Answer 4

For checking current time or any time between two times ::

NSCalendar *calendar = [[NSCalendar alloc]
                        initWithCalendarIdentifier:NSGregorianCalendar];
NSCalendarUnit units = NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit | NSHourCalendarUnit | NSMinuteCalendarUnit;
NSDateComponents *components = [calendar components:units fromDate:[NSDate date]];

return [self isDateComponent:components withinStartHour:startH startMin:startM endHour:endH endMin:endM];

---

-(BOOL)isDateComponent:(NSDateComponents*)components withinStartHour:(int)startH startMin:(int)startM endHour:(int)endH endMin:(int)endM
{
    if (endH < startH) {
        return (  [self isDateComponent:components betweenStartHour:startH startmin:startM endHour:23 endMin:59]  ||
                [self isDateComponent:components betweenStartHour:0 startmin:0 endHour:endH endMin:endM]  );
    }
    else {
        return [self isDateComponent:components betweenStartHour:startH startmin:startM endHour:endH endMin:endM];
    }


}



-(BOOL)isDateComponent:(NSDateComponents*)components betweenStartHour:(int)startH startmin:(int)startM endHour:(int)endH endMin:(int)endM
{

    int currentH = components.hour;
    int currentM = components.minute ;

    DDLogVerbose(@"start : %i-%i, end : %i-%i, current:%i-%i",startH,startM,endH,endM,currentH,currentM);
    startM  = startM + startH * 60;
    endM = endM + endH * 60;

    currentM = components.minute + currentH*60;

    if ( startM <= currentM && currentM < endM ) {
        return YES;
    }
    else {
        return NO;
    }


}

Answer 5

NSDate *now = [NSDate date];
if (([now compare:earlierDateVariable] == NSOrderedDescending) && ([now compare:laterDateVariable] == NSOrderedAscending ))
{
    // Do something here...
}

To set earlierDate and laterDate, straight from Apple's documentation available here

NSDateComponents *comps = [[NSDateComponents alloc] init];
[comps setDay:22];
[comps setMonth:03];
[comps setYear:2011];
[comps setHour:21];
[comps setMinute:00];
NSCalendar *gregorian = [[NSCalendar alloc]
    initWithCalendarIdentifier:NSGregorianCalendar];
NSDate *earlierDateVariable = [gregorian dateFromComponents:comps];
[comps release];
[gregorian release];

And the same goes for later date...

Answer 6

If anybody needs, this is a code to create sections in a tableView according to the date of objects.

Method to get dates for today, yesterday, etc. (taken from ReMail project DateUtil class):

#define DATE_UTIL_SECS_PER_DAY 86400

-(void)refreshData {
    //TODO(gabor): Call this every hour or so to refresh what today, yesterday, etc. mean
    NSCalendar *gregorian = [NSCalendar currentCalendar];
    self.today = [NSDate date];
    self.yesterday = [today dateByAddingTimeInterval:-DATE_UTIL_SECS_PER_DAY];
    self.lastWeek = [today dateByAddingTimeInterval:-6*DATE_UTIL_SECS_PER_DAY];
    self.todayComponents = [gregorian components:(NSYearCalendarUnit|NSMonthCalendarUnit|NSDayCalendarUnit) fromDate:today];
    self.yesterdayComponents = [gregorian components:(NSYearCalendarUnit|NSMonthCalendarUnit|NSDayCalendarUnit) fromDate:yesterday];
    self.dateFormatter = [[[NSDateFormatter alloc] init] autorelease];
}

Method to sort tableData for table view sections according to date:

// Sort tableData objects according to the date
    for (MCMessage *mcMessage in self.tableData) {
        NSDateComponents *components = [[NSCalendar currentCalendar] components:NSDayCalendarUnit | NSMonthCalendarUnit | NSYearCalendarUnit fromDate:mcMessage.dateTime];
        NSInteger day = [components day];
        NSInteger month = [components month];
        NSInteger year = [components year];

        NSLog(@"Day:%d, Month:%d, Year:%d. Today day:%d. Yesterday:%d", day, month, year, dateUtil.todayComponents.day, dateUtil.yesterdayComponents.day);

        if ((dateUtil.todayComponents.day == day) && (dateUtil.todayComponents.month == month) && (dateUtil.todayComponents.year == year))
        {
            [self.todayData addObject:mcMessage];
        }
        else if ((dateUtil.yesterdayComponents.day == day) && (dateUtil.yesterdayComponents.month == month) && (dateUtil.yesterdayComponents.year == year))
        {
            [self.yesterdayData addObject:mcMessage];
        }
        else
        {
            [self.soonerData addObject:mcMessage];
        }
    }