Number of days from now until date entered by user

[Pudding]

Hello everyone,

I'd like to implement into my app a countdown of days until an expiration date that the user enters. I have 3 text fields; month, day, year. And a label; daysLabel. I'd like the user to be able to enter any date using the 3 text fields and when pressing an IBAction, daysLabel will display the amount of days until the expiration date. So far this is what I have and obviously it's not working:

    
- (IBAction)calcDays:(id)sender {

    NSDateFormatter *dateformatter = [[NSDateFormatter alloc] init];
    [dateformatter setDateFormat:@"MM/dd/yyyy hh:mm:ss"];
    
    NSString *next = [[NSString alloc] initWithFormat: @"%@/%@/%@ 12:00:00 am", month.text, day.text, year.text];
    
    NSDate *nextDate = [dateformatter dateFromString:next];
    NSDate *today = [[NSDate alloc] init];
    NSTimeInterval time = [today timeIntervalSinceDate:nextDate];
    double numdays = time / 86400;
    NSLog(@"numdays = %f/n", numdays);
    
    [daysLabel setText:[NSString stringWithFormat:@"%f", numdays]];
    [dateformatter release];
    [next release];
}

Hope this isn't too dumb a question. Any help would be very much appreciated. Thank you all..

[SundialSoft]

Originally Posted by Pudding

Hello everyone,

I'd like to implement into my app a countdown of days until an expiration date that the user enters. I have 3 text fields; month, day, year. And a label; daysLabel. I'd like the user to be able to enter any date using the 3 text fields and when pressing an IBAction, daysLabel will display the amount of days until the expiration date. So far this is what I have and obviously it's not working:

    
- (IBAction)calcDays:(id)sender {

    NSDateFormatter *dateformatter = [[NSDateFormatter alloc] init];
    [dateformatter setDateFormat:@"MM/dd/yyyy hh:mm:ss"];
    
    NSString *next = [[NSString alloc] initWithFormat: @"%@/%@/%@ 12:00:00 am", month.text, day.text, year.text];
    
    NSDate *nextDate = [dateformatter dateFromString:next];
    NSDate *today = [[NSDate alloc] init];
    NSTimeInterval time = [today timeIntervalSinceDate:nextDate];
    double numdays = time / 86400;
    NSLog(@"numdays = %f/n", numdays);
    
    [daysLabel setText:[NSString stringWithFormat:@"%f", numdays]];
    [dateformatter release];
    [next release];
}

Hope this isn't too dumb a question. Any help would be very much appreciated. Thank you all..

I have 2 appstore apps both with countdowns so I can help. First point, user interface guidelines: Apple expect you to use a date picker. Have you considered that?

Here is code from one of my apps working out the chosen date & today's date as days for comparison. Something like this may suit you.

    NSCalendar *curCalendar = [NSCalendar currentCalendar]; 
    NSDateFormatter *df = [[NSDateFormatter alloc] init];
    NSInteger tempyr;// = [dateComponents year];
    NSInteger tempmo;// = [dateComponents mon];
    NSInteger tempda;// = [dateComponents day];
    
    unsigned unitFlags = NSYearCalendarUnit | NSMonthCalendarUnit |  NSDayCalendarUnit;
    NSDateComponents *dateComponents = [curCalendar components:unitFlags fromDate:[NSDate date]];
    // check for the date picked being in the future 
    tempyr = [dateComponents year] * 365;//get num days
    tempmo = [dateComponents month] * 30;//
    tempda = [dateComponents day];
    NSInteger todayAsDays = tempyr+tempmo+tempda;
    
    dateComponents = [curCalendar components:unitFlags fromDate:datePicker.date];
    tempyr = [dateComponents year] * 365;//get num days
    tempmo = [dateComponents month] * 30;//was 12
    tempda = [dateComponents day];
    NSInteger endDateDays = tempyr+tempmo+tempda;

This is an ARC app so no retain release stuff.