Convert A NSString into NSDate to add days to the dynamic date

Question

I am getting a NSString(in which i have a date)from database, I need to add days like suppose 10//12/15/45/60 days to the date, How can I do it.

when I am trying with this piece of code :

NSString *expiryDateStr = [NSString stringWithFormat:@"%@",[[assets valueForKeyPath:@"assetrewards.expirydate"] objectAtIndex:0]];
        NSLog(@" date %@",expiryDateStr);

        //DATE FORMATTER
        NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init];
        [dateFormat setDateFormat:@"dd/MM/yyyy"];
        NSDate *_date = [dateFormat dateFromString:expiryDateStr];
        [dateFormat setDateFormat:[NSString stringWithFormat:@"dd MMM yyyy HH:mm"]];
        [dateFormat setTimeZone:[NSTimeZone timeZoneForSecondsFromGMT:3600*5]];
        NSLog(@"date format %@",dateFormat);
        NSLog(@"Date: %@", _date);

I am getting output like this :

date 07/10/2013
date format <NSDateFormatter: 0x9f9d4a0>
Date: 2013-10-06 18:30:00 +0000

the date is getting changed, I am not knowing where i am going wrong, if that is the correct date how to add the days to the date.

check this link for date formate http://iosdevelopertips.com/cocoa/date-formatters-examples-take-3.html — Darshan Kunjadiya, Jul 23 '13 at 11:33
Perfectly correct results for India. (The x:30 timezone offset is a dead giveaway.) — Hot Licks, Jul 23 '13 at 12:14
Note that the second setDateFormat/setTimezone has no effect, since the dateFormatter is unused after that. — Hot Licks, Jul 23 '13 at 12:20

score 2 · Accepted Answer · answered Jul 23 '13 at 12:55

NSString *expiryDateStr = @"07/10/2013";
NSLog(@" date %@",expiryDateStr);
expiryDateStr=[expiryDateStr stringByAppendingString:@" 00:00:00 +000"];
//DATE FORMATTER
NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init];
[dateFormat setDateFormat:@"dd/MM/yyyy HH:mm:ss Z"];
NSDate *_date = [dateFormat dateFromString:expiryDateStr];
[dateFormat setDateFormat:[NSString stringWithFormat:@"dd MMM yyyy HH:mm"]];
[dateFormat setTimeZone:[NSTimeZone timeZoneForSecondsFromGMT:0]];
NSDateComponents *components = [[NSCalendar currentCalendar] components:NSDayCalendarUnit | NSMonthCalendarUnit | NSYearCalendarUnit |NSHourCalendarUnit | NSMinuteCalendarUnit |NSSecondCalendarUnit fromDate:_date];
NSInteger day = [components day]+1; // U can add as per your requirement


[components setDay:day];
NSDate *NextDate = [[NSCalendar currentCalendar] dateFromComponents:components];

NSLog(@"Next Date: %@", NextDate);

There is really no need to append the time to the date string. The time 00:00:00 will be the default. And, as I said above, the second setDateFormat and the setTimeZone aren't doing anything (and that time zone should not be used unless it was used to convert the original date). — Hot Licks, Jul 23 '13 at 15:15

NiravPatel · Answer 2 · 2013-07-23T12:03:32.757

0

you can and days into date like below...

set timezone like below...

  [dateFormat setTimeZone:[NSTimeZone timeZoneForSecondsFromGMT:0]];


    NSDate *dateAftertwenty = [NSDate dateWithTimeInterval:10*24*60*60 sinceDate:date]; //TimeInterval is of 10 days....you can set any number of days.24 is hours, 60 is minutes and 60 is seconds at last..

Let me know it is working or not!!!

Happy Coding!!!!

edited Jul 23 '13 at 12:03

answered Jul 23 '13 at 11:34

NiravPatel

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1st i need to convert the string value which is having date to NSDate, that i am unable to do. – iOSDev Jul 23 '13 at 11:45
just use format [dateFormat setDateFormat:@"MMM/dd/yyyy"]; ,just check, is it giving correct date you want or not...?? – NiravPatel Jul 23 '13 at 11:55
I am getting null value – iOSDev Jul 23 '13 at 11:59
Still i am getting the null value while converting it to the NSDate object – iOSDev Jul 23 '13 at 12:12
The date format "dd/MM/yyyy" was working just fine, so it's no surprise that "MMM/dd/yyyy" fails. – Hot Licks Jul 23 '13 at 12:23

Paras Joshi · Answer 3 · 2013-07-23T12:52:56.933

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UPDATE:

First setTimeZone to localTimeZone like bellow..

[formatter setLocale:[NSLocale currentLocale]];
[formatter setTimeZone:[NSTimeZone timeZoneForSecondsFromGMT:0]];

Convert that String Date to NSDate with my bellow method..

-(NSDate *)convertStringToDate:(NSString *) date dateFormat:(NSString*)dateFormat{
    NSDateFormatter *formatter = [[[NSDateFormatter alloc] init] autorelease];
    [formatter setLocale:[NSLocale currentLocale]];
    [formatter setTimeZone:[NSTimeZone timeZoneForSecondsFromGMT:0]];
    NSDate *nowDate = [formatter setDateFormat:dateFormat];// set format here which format in string date
    date = [date stringByReplacingOccurrencesOfString:@"+0000" withString:@""];
    nowDate = [formatter dateFromString:date];
    // NSLog(@"date============================>>>>>>>>>>>>>>> : %@", nowDate);
    return nowDate;
}

and Use it like bellow..

NSDate *startDate = [self convertStringToDate:@"07/10/2013" dateFormate:@"dd/MM/yyyy"];

above set date formate which format is define in string

edited Jul 23 '13 at 12:52

answered Jul 23 '13 at 11:36

Paras Joshi

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@iOSDev you try it out?? whats the problem?? – Paras Joshi Jul 23 '13 at 12:04
1stly i want to convert the NSString into NSDate. I am having problem there once, this is clear i will be able to move the next step . – iOSDev Jul 23 '13 at 12:15
@iOSDev i updated answer dude try it out and let me know.. :) – Paras Joshi Jul 23 '13 at 12:20
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@iOSDev -- You quite successfully converted the string to an NSDate. You're failing to appreciate that when you NSLog an NSDate object you get UTC, not your local timezone. – Hot Licks Jul 23 '13 at 12:21
@HotLicks yes right and for that now i also add this line `[dateFormat setTimeZone:[NSTimeZone localTimeZone]];` .. :) – Paras Joshi Jul 23 '13 at 12:23
@iOSDev - localTimeZone is what NSDateFormatter defaults to. – Hot Licks Jul 23 '13 at 12:41
@iOSDev in which you test it?? Simulator or iPhone Device?? if Simulator then check the location – Paras Joshi Jul 23 '13 at 12:45
I have checked in simulator – iOSDev Jul 23 '13 at 13:26

score 0 · Answer 4 · answered Jul 23 '13 at 12:29

NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init];
[dateFormat setDateFormat:@"dd/MM/yyyy"];
NSDate *_date = [dateFormat dateFromString:expiryDateStr];

is perfectly fine -- no problem. The "problem" is that

NSLog(@"Date: %@", _date);

will display the date as UTC/GMT, and hence (in India) a value five and a half hours earlier than the "real" date. This is not a problem -- when you format the date into a different string format (with the second incarnation of the date formatter) then it will come out correctly (so long as you DO NOT set the timezone for that version, if you didn't set it for the first).

To increment the date it's usually best to use NSDateComponents (more or less as shown by Paras) vs simply adding increments of 24 hours, in case there is any sort of "daylight savings time" transition in the date range.

iphondroid · Answer 5 · 2013-07-23T13:18:06.027

I have modified your code and I believe this is what you want:

NSString *expiryDateStr = @"07/10/2013";
NSLog(@" date %@",expiryDateStr);

//DATE FORMATTER
NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init];
[dateFormat setDateFormat:@"dd/MM/yyyy"];

[dateFormat setTimeZone:[NSTimeZone timeZoneWithAbbreviation:@"GMT"]];
NSDate *_date = [dateFormat dateFromString:expiryDateStr];
NSLog(@"date format %@",dateFormat);
NSLog(@"Date: %@", _date);

Output:
date 07/10/2013
date format
Date: 2013-10-07 00:00:00 +0000

Now changed the time zone in the code:

NSString *expiryDateStr = @"07/10/2013";
NSLog(@" date %@",expiryDateStr);

//DATE FORMATTER
NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init];
[dateFormat setDateFormat:@"dd/MM/yyyy"];

[dateFormat setTimeZone:[NSTimeZone timeZoneWithAbbreviation:@"GMT+5:30"]];
NSDate *_date = [dateFormat dateFromString:expiryDateStr];
NSLog(@"date format %@",dateFormat);
NSLog(@"Date: %@", _date);

And the output is:

date 07/10/2013
date format
Date: 2013-10-06 18:30:00 +0000

This is the output you were getting. This is because your time zone from your computer is being used.

EDIT(Number of days to add is denoted by days integer ):

NSString *expiryDateStr = @"07/10/2013";
NSLog(@" date %@",expiryDateStr);

//DATE FORMATTER
NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init];
[dateFormat setDateFormat:@"dd/MM/yyyy"];


[dateFormat setTimeZone:[NSTimeZone timeZoneWithAbbreviation:@"GMT"]];
NSDate *_date = [dateFormat dateFromString:expiryDateStr];
NSInteger days = 30;
_date = [_date dateByAddingTimeInterval:(60*60*24*days)];

NSLog(@"date format %@",dateFormat);
NSLog(@"Date: %@", _date);

Output of EDITed code:

date 07/10/2013
date format
Date: 2013-11-06 00:00:00 +0000

could u please add the code for adding number of days to the date, dat would complete the answer. — iOSDev, Jul 23 '13 at 13:04
i am getting null value, Thank u so much , and @Cook patel, answer worked out for me. — iOSDev, Jul 23 '13 at 13:26

Convert A NSString into NSDate to add days to the dynamic date

5 Answers5