I have the date function.And I have to compare the previous date with current data in iphone
For current date I have code:-
NSDate* date = [NSDate date];
//Create the dateformatter object
NSDateFormatter* formatter = [[[NSDateFormatter alloc] init] autorelease];
//Set the required date format
[formatter setDateFormat:#"yyyy-MM-dd"];
//Get the string date
NSString* str = [formatter stringFromDate:date];
//Display on the console
NSLog(str);
//Set in the lable
[dateLabel setText:str];
But I want to implement the compare the current date & previous date in iphone
Thanks in advance
You can compare dates using NSDate's comparison methods:
- (NSDate *)earlierDate:(NSDate *)anotherDate;
- (NSDate *)laterDate:(NSDate *)anotherDate;
- (NSComparisonResult)compare:(NSDate *)other;
- (BOOL)isEqualToDate:(NSDate *)otherDate;
Check NSDate class reference to know more..
Related
I have a string date in UTC format:
"2012-11-20T05:23:02.34"
now I want the UTC NSDate object for this... and I implemented this function.
+ (NSDate *)utcDateFromString:(NSString *)string withFormat:(NSString *)format {
NSDateFormatter *inputFormatter = [[NSDateFormatter alloc] init];
inputFormatter.timeZone =[NSTimeZone timeZoneWithAbbreviation:#"UTC"];
[inputFormatter setDateFormat:format];
NSDate *date = [inputFormatter dateFromString:string];
[inputFormatter release];
return date;
}
and called it like this...
NSDate* submittedDate =[NSDate utcDateFromString:submittedDateString withFormat:#"YYYY-MM-dd'T'HH:mm:ss.SS"];
but this returns the NSDate description as this..
2011-11-20 05:23:02 +0000
Now if you notice there is one year difference in the dates... can anyone explain why is this happening..?
Thanks for your help.
in the dateformmater, use yyyy instead of YYYY
It should be
NSDate* submittedDate =[NSDate utcDateFromString:submittedDateString withFormat:#"yyyy-MM-dd'T'HH:mm:ss.SS"];
That will solve the problem.
In the following link, search for YYYY.
https://developer.apple.com/library/mac/#documentation/Cocoa/Conceptual/DataFormatting/Articles/dfDateFormatting10_4.html
It uses yyyy to specify the year component. A common mistake is to use YYYY. yyyy specifies the calendar year whereas YYYY specifies the year (of “Week of Year”), used in the ISO year-week calendar. In most cases, yyyy and YYYY yield the same number, however they may be different. Typically you should use the calendar year.
try this bellow method..
-(NSDate *)getUTCFormateDate:(NSString *)localDate withFormat:(NSString *)format
{
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:format];
NSTimeZone *timeZone = [NSTimeZone timeZoneWithName:#"UTC"];
[dateFormatter setTimeZone:timeZone];
NSDate *date = [dateFormatter dateFromString:localDate];
return date;
}
And Use Like bellow..
NSDate *dateHere = [[NSDate alloc]init];
dateHere = [self getUTCFormateDate:#"2012-11-20T05:23:02.34" withFormat:#"yyyy-MM-dd'T'HH:mm:ss.SS"];
NSLog(#"Date here %#",dateHere);
and i get output is Date here 2012-11-20 05:23:02 +0000
see my another answer which return string date with UTF format..
convert NSstring date to UTC dateenter link description here
I am getting the rfc3399 formatted date string through google calender web services. I want to convert this string into NSDate object so that I can add an event about this to the local calendar. I found the below method in Apple's documentation regarding NSDateFormatter , but its not working
Date String - 2012-05-23T18:30:00.000-05:00
- (NSString *)userVisibleDateTimeStringForRFC3339DateTimeString:(NSString *)rfc3339DateTimeString {
/*
Returns a user-visible date time string that corresponds to the specified
RFC 3339 date time string. Note that this does not handle all possible
RFC 3339 date time strings, just one of the most common styles.
*/
NSDateFormatter *rfc3339DateFormatter = [[NSDateFormatter alloc] init];
NSLocale *enUSPOSIXLocale = [[NSLocale alloc] initWithLocaleIdentifier:#"en_US_POSIX"];
[rfc3339DateFormatter setLocale:enUSPOSIXLocale];
[rfc3339DateFormatter setDateFormat:#"yyyy'-'MM'-'dd'T'HH':'mm':'ss'Z'"];
[rfc3339DateFormatter setTimeZone:[NSTimeZone timeZoneForSecondsFromGMT:0]];
// Convert the RFC 3339 date time string to an NSDate.
NSDate *date = [rfc3339DateFormatter dateFromString:rfc3339DateTimeString];
NSString *userVisibleDateTimeString;
if (date != nil) {
// Convert the date object to a user-visible date string.
NSDateFormatter *userVisibleDateFormatter = [[NSDateFormatter alloc] init];
assert(userVisibleDateFormatter != nil);
[userVisibleDateFormatter setDateStyle:NSDateFormatterShortStyle];
[userVisibleDateFormatter setTimeStyle:NSDateFormatterShortStyle];
userVisibleDateTimeString = [userVisibleDateFormatter stringFromDate:date];
}
return userVisibleDateTimeString;
}
Please help me , I have tried changing the date format quite a lot times but no success.
try with this method..
-(NSDate *)convertStringToDate:(NSString *) date {
NSDateFormatter *formatter = [[[NSDateFormatter alloc] init] autorelease];
NSDate *nowDate = [[[NSDate alloc] init] autorelease];
[formatter setDateFormat:#"YYYY-MM-DD'T'HH:mm:ssZ"];// set format here which format in string date
/// also try this format #"yyyy-MM-dd'T'HH:mm:ss.fffK"
date = [date stringByReplacingOccurrencesOfString:#"+0000" withString:#""];
nowDate = [formatter dateFromString:date];
// NSLog(#"date============================>>>>>>>>>>>>>>> : %#", nowDate);
return nowDate;
}
call this method like bellow..
NSDate *date = [self convertStringToDate:rfc3339DateTimeString];
also for try with some rfc Date formate with fffK for this format see this bellow. link..
how-do-i-parse-and-convert-datetimes-to-the-rfc-3339-date-time-format
i hope this answer is helpful
The issue is the date contains (-05:00 )':' in the timezone value ... you have to remove it from the string then the above method will work fine......The new date string should look like below
2012-05-23T18:30:00.000-0500 - This should be the right format .
I have two times :
10:23:51
10:31:54
Both values are stored as strings in a SQLite database.
I want to find the difference between these two times in hh:mm format.
How can I do this?
I have searched a lot. But can't find a proper solution.
Help me out.
Thanks.
Edit :
See basically I am having two arrays:
InTimeArray and OuttimeArray.
Now in the viewDidload method , I am fetching all the intime entries in the IntimeArray and Outtime entries in the outtime Arrays.
Now I am passing one by one values in tableview like in 1st row
IntimeArray[0]
OuyTimeArray[0]
second row:
IntimeArray[1]
OuyTimeArray[1]
Now I want to count the differences between 1st row's intime and outtime in HH:MM format.
I am really confused.
you can take a look at that :
-(NSDate *)dateFromString:(NSString *)string
{
NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init];
NSLocale *locale = [[NSLocale alloc] initWithLocaleIdentifier:#"en_US"];
[dateFormat setLocale:locale];
[dateFormat setDateFormat:#"HH:mm:ss"];
NSDate *date1 = [dateFormat dateFromString:string];
if(!date1) date1= [NSDate date];
[dateFormat release];
[locale release];
return date1;
}
this will turn the NSDate to you and when you change them both to NSDates then you can learn the difference by looking at this.
i hope this will help you..
You have to first change your both strings into date format using this method :-
- (NSDate *)dateFromString:(NSString *)string;
after that you just have to calculate number of seconds between both the dates.Thats it.
OR there is another simple way to do this. i.e.
get dates from both arrays first like this:-
NSDate *eventStartDate = [IntimeArray objectAtIndex:indexpath.row];
NSDate *eventEndDate = [OuyTimeArray objectAtIndex:indexpath.row];
Then calculate difference between both the dates like this :-
NSTimeInterval startTimeInterval = [eventStartDate timeIntervalSinceDate:currentDate];
Hope it helps Thanks :)
Try this:
NSDateFormatter *formatter = [[[NSDateFormatter alloc] init] autorelease];
[formatter setDateFormat:#"HH:mm:ss"];
NSDate *d1 = [formatter dateFromString:IntimeArray[0]];
NSDate *d2 = [formatter dateFromString:OuyTimeArray[0]];
NSTimeInterval ti = [d2 timeIntervalSinceDate:d1];
float hours = floor(ti / 3600);
float minutes = floor((ti - hours*3600) / 60);
NSString *s = [NSString stringWithFormat:#"%02.0f:%02.0f",hours,minutes];
For your given example, NSLog(#"Time passed: %#",s); will print 00:08.
I am using UIDatePicker in my app and when i take the date that was chosen with:
NSDate *date = picker.date;
picker.date returned the day before the date that I chose.
any idea why it happens?
UIDatePicker will be displaying dates and times in your local timezone. However, NSDate does not have any concept of a timezone as it stores an absolute number of seconds since a reference date. When NSLogging a date, it shows the date and time in GMT. I expect if you work out your local timezone difference from GMT, you will see that it is the correct date.
Try creating an NSDateFormatter or NSCalendar with the appropriate locale and pass the date through that.
For further reading on this common topic, see this site written by another SO contributor.
give this a try worked for me
NSDate* sourceDate = [NSDate date];
NSTimeZone* sourceTimeZone = [NSTimeZone timeZoneWithAbbreviation:#"GMT"];
NSTimeZone* destinationTimeZone = [NSTimeZone systemTimeZone];
NSInteger sourceGMTOffset = [sourceTimeZone secondsFromGMTForDate:sourceDate];
NSInteger destinationGMTOffset = [destinationTimeZone secondsFromGMTForDate:sourceDate];
NSTimeInterval interval = destinationGMTOffset - sourceGMTOffset;
NSDate* destinationDate = [[[NSDate alloc] initWithTimeInterval:interval sinceDate:sourceDate] autorelease];
//i'm outputting mine in a label you can use anything you like
NSString *dateOutput = [[[NSString alloc] initWithFormat:#"%#", destinationDate]autorelease];
self.dateLabel.text = dateOutput;
Remember to create the NSDate and then output it with a valid timezone and calendar!
NSDate only represents an absolute point in time. It has no concept of timezone (NY, Barcelona, ...) or calendar (Gregorian, Hebrew, ...).
UIDatePicker returns by default a NSDate with the system NSCalendar and NSTimeZone, but when you try to print it later, you do not format the output. You may have there the mismatch.
So 1st you need to setup the UIDatePicker correctly and 2nd transform the output with the NSDateFormatter so it knows the Calendar and the TimeZone being used.
An example code with the init of the UIDatePicker and then printing the result:
- (void)viewDidLoad
{
[super viewDidLoad];
// init the UIDatePicker with your values
// by default UIDatePicker inits with today, system calendar and timezone
// Only for teaching purposes I will init with default values
NSDate * now = [[NSDate alloc] init];
[_datePicker setDate: now]
animated: YES];
_datePicker.timeZone = [NSTimeZone localTimeZone];
_datePicker.calendar = [NSCalendar currentCalendar];
[_datePicker addTarget: self
action: #selector(getDatePickerSelection:)
forControlEvents:UIControlEventValueChanged];
}
-(void)getDatePickerSelection:(id) sender
{
// NSDateFormatter automatically inits with system calendar and timezone
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
// Setup an output style
[dateFormatter setDateStyle:NSDateFormatterMediumStyle];
[dateFormatter setTimeStyle:NSDateFormatterShortStyle];
// Medium style date, short style time => "Nov 23, 1937 3:30pm"
NSString *dateString = [dateFormatter stringFromDate:date];
}
Check the answer I did for another very similar question:
NSDate output using NSDateFormatter
Did you check the timezone?
When you print an NSDate it will use GMT as it timezone.
If you set the system timezone to the NSDateFormatter you might get an other date, because it will take the timezone and calculate the time accordingly.
Add this code and see if the output is correct:
NSDate *date = picker.date;
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateStyle:NSDateFormatterMediumStyle];
[dateFormatter setTimeZone:NSDateFormatterNoStyle];
[dateFormatter setLocale:[NSLocale currentLocale]];
NSLog(#"Date: %#", [dateFormmater stringFromDate:date]);
[dateFormatter release], dateFormatter = nil;
Just add one line of code
self.datePicker.timeZone = [NSTimeZone timeZoneForSecondsFromGMT:0];
0 is for GMT 00 . Add according to your time zone.
I want to pass two dates 1st which i will select from the datetime picker & 2nd the current date of the iPhone then what is the process for the current date to pass to the webservice.
You can pass current date as a string through url.
NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
[formatter setDateFormat:#"yy-MM-dd"];
NSString *dateString=[formatter stringFromDate:[NSDate date]];
NSLog(#"Today is %#",dateString);