I have a date in timestamp which looks something like this: 1474914600000
Now, I want to covert this timestamp to NSDate in format of dd-mm-yyyy.
How can this be done in objective c?
You need to convert your timestamp to NSDate and then get NSDate in your desired format. Also your timestamp seems to be in millisecond so you will have to divide it be 1000. You can use below code:
double timeStamp = 1474914600000;
NSTimeInterval timeInterval=timeStamp/1000;
NSDate *date = [NSDate dateWithTimeIntervalSince1970:timeInterval];
NSDateFormatter *dateformatter=[[NSDateFormatter alloc]init];
[dateformatter setDateFormat:#"dd-MM-yyyy"];
NSString *dateString=[dateformatter stringFromDate:date];
dateString value as an output will be: "27-09-2016"
Hope it helps.
To elaborate on balkaran's answer incase you're new to the iOS world. The timestamp you provided seems to go down to milliseconds which you wouldn't need for day times that's why he's dividing by 1000. You would use the dateformatter as follows to return an NSString you can use with the formatted date.
NSDate *date = [NSDate dateWithTimeIntervalSince1970:1474914600000];
NSDateFormatter *formatter = [NSDateFormatter new];
formatter.dateFormat = #"dd-MM-yyyy";
NSString *formattedDate = [formatter stringFromDate:date];
use this:
NSDate *date = [NSDate dateWithTimeIntervalSince1970:timeStamp/1000];
then convert your date in the format you want.
Related
I need to display the current Date and Time.
I have used ;
NSDate *currentDateNTime = [NSDate date];
I want to have the current date and time (Should display the system time and not GMT time).
The output should be in a NSDate format and not NSString.
for example;
NSDate *currentDateNTime = [NSDate date];
// Do the processing....
NSDate *nowDateAndTime = .....; // Output should be a NSDate and not a NSString
Since all NSDate is GMT referred, you probably want this:
(don'f forget that the nowDate won't be the actual current system date-time, but it's "shifted", so if you will generate NSString using NSDateFormatter, you will see a wrong date)
NSDate* currentDate = [NSDate date];
NSTimeZone* currentTimeZone = [NSTimeZone timeZoneWithAbbreviation:#"GMT"];
NSTimeZone* nowTimeZone = [NSTimeZone systemTimeZone];
NSInteger currentGMTOffset = [currentTimeZone secondsFromGMTForDate:currentDate];
NSInteger nowGMTOffset = [nowTimeZone secondsFromGMTForDate:currentDate];
NSTimeInterval interval = nowGMTOffset - currentGMTOffset;
NSDate* nowDate = [[NSDate alloc] initWithTimeInterval:interval sinceDate:currentDate];
Every moment in time is the same moment in time everywhere around the world —- it is just expressed as different clock times in different timezones. Therefore, you can't change the date to some other date that represents the time in your timezone; you must use an NSDateFormatter that you feed with the timezone you are in. The resulting string is the moment in time expressed in the clock time of your position.
Do all needed calculations in GMT, and just use a formatter for displaying.
Worth reading
Does [NSDate date] return the local date and time?
Some useful resources for anyone coming to this more recently:
Apple date and time programming guide do read it if you're doing anything serious with dates and times.
https://developer.apple.com/library/content/documentation/Cocoa/Conceptual/DatesAndTimes/DatesAndTimes.html#//apple_ref/doc/uid/10000039i?language=objc
Useful category on NSDate with lots of utilities does allow a ~new~ date to be generated based on an existing date.
https://github.com/erica/NSDate-Extensions
There's also a swift version of the category
https://github.com/erica/SwiftDates
You need an NSDateFormatter and call stringFromDate this method to get a string of your date.
NSDateFormatter *dateformater = [[NSDateFormatter alloc] init];
[dateformater setDateFormat:#"yyyyMMdd,HH:mm"];
NSString *str = [dateformater stringFromDate: currentDateNTime];
use this method
-(NSDate *)convertDateToDate:(NSDate *) date
{
NSDateFormatter *formatter = [[[NSDateFormatter alloc] init] autorelease];
NSDate *nowDate = [[[NSDate alloc] init] autorelease];
[formatter setTimeZone:[NSTimeZone timeZoneForSecondsFromGMT:0]];
[formatter setDateFormat:#"yyyy-MM-d H:m:s"];
NSString * strdate = [formatter stringFromDate:date];
nowDate = [formatter dateFromString:strdate];
return nowDate;
}
this may return you what you want.
i hope you this may help you.
I must initialize an NSDate object from NSString in objective-c. I do it like this:
NSString *dateString = [[webSentence child:#"DateTime"].text stringByReplacingOccurrencesOfString:#"T" withString:#" "];
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:#"yyyy-mm-dd HH:mm:ss"];
[dateFormatter setTimeZone:[NSTimeZone timeZoneWithName:#"Europe/Budapest"]];
NSDate *date = [[NSDate alloc] init];
date = [dateFormatter dateFromString:dateString];
E.g: when I try it with string value #"2011-01-02 17:49:54" I get an NSDate 2011-01-02 16:49:54 +0000. As you can see there is a one hour difference between the two values. NSDate has a wrong value, it should be exactly the same I defined in my string in the timezone I set in dateFormatter. It seems it uses my date defined it string as UTC, even if I set its timezone to "Europe/Budapest". How can I fix this problem?
Thanks!
NSDate stores dates relative to a standard reference date. From the class docs:
"The sole primitive method of NSDate, timeIntervalSinceReferenceDate, provides the basis for all the other methods in the NSDate interface. This method returns a time value relative to an absolute reference date—the first instant of 1 January 2001, GMT."
NSDate does not itself have any concept of time zones. So the NSDateFormatter did the right thing: it converted a date which you told it had a GMT offset (by specifying a time zone), and gave you a "normalized" NSDate for that date.
If you want to see the date represented in the Europe/Budapest time zone, either use your existing date formatter (-stringFromDate:) or the appropriate NSDate description method (e.g. -descriptionWithCalendarFormat:timeZone:locale:).
P.S.- You don't need an alloc/init at all in your code as written. In non-ARC that would be a leak.
P.P.S.- Your date format is incorrect and giving nonsensical results. I've gone ahead and cleaned up your code as follows (tested under ARC):
NSString *dateString = #"2011-09-02 17:49:54";
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
NSTimeZone *tz = [NSTimeZone timeZoneWithName:#"Europe/Budapest"];
[dateFormatter setDateFormat:#"yyyy-MM-dd HH:mm:ss"];
[dateFormatter setTimeZone:tz];
NSDate *date = [dateFormatter dateFromString:dateString];
NSLog(#"%#", [dateFormatter stringFromDate:date]);
NSLog(#"%#", [date descriptionWithCalendarFormat:nil timeZone:tz locale:nil]);
Two things:
1) you have an error in your date format string. You should use MM for month, not mm (lowercase mm is for minutes)
2) after you create you NSDate object, you'll need to use the NSDateFormatter method stringFromDate: to generate a date string localized to a particular timezone. If you just do a straight NSLog() on the NSDate object it will show the date as GMT by default (GMT is one hour behind Budapest time)
My dateFromString is not working and i'm not sure why
NSString *purchase = #"2011-09-30 17:47:57";
NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init];
[dateFormat setDateFormat:#"yyyy-MM-dd hh:mm:ss"];
NSDate *date = [dateFormat dateFromString:purchase];
date is 'invalid CFStringRef'
See anything i might be overlooking?
Try changing the hours in the formatter to capitals, i.e. yyyy-MM-dd HH:mm:ss
I'm not sure if that will solve your error, but that is the correct way to parse a 24 hour time
in the format
"hh" means Hour [1-12].
"HH" means Hour [0-23].
See UTS Date Field Symbol Table for the date format specifiers.
Try this:
NSString *purchase = #"2011-09-30 17:47:57";
NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init];
[dateFormat setDateFormat:#"yyyy-MM-dd HH:mm:ss"];
NSDate *date = [dateFormat dateFromString:purchase];
Date Formatters Guide - HH is used for 24 hour times, hh for 12 hour.
If you mean that "date" is not accepted as an NSString by another function, that's because it's not a string, it's an NSDate.
(Where, precisely, are you getting the error message, and what is the full text?)
I want to ask 2 questions about the NSDate of iPhone application.
1) How to set the
NSDate *startDay to 01-01-2010 and NSDate *endDay to 31-12-2010
2) how many day between the startDay and the endDay.
What should I do? Thank you very much.
For handling dates with different formats you would need to use NSDateFormatter
NSDateFormatter *format = [[NSDateFormatter alloc] init];
[format setDateFormat:#"mm-dd-yyyy"];
To get date with specified format
NSString *dateString = [format stringFromDate:date];
To create a date from string with specified format:
NSDate *date = [format dateFromString:dateString];
NSDateFormatter documentation
To find the difference between two dates:
NSTimeInterval interval = [endDay timeIntervalSinceDate:startDay];
timeIntervalSinceDate documentation
I've got a string representation of a time, like "11:13 AM." This was produced using an NSDateFormatter and the stringFromDate: method.
I'd like to compare this time to the current time, but when I use the dateFromString: method to turn the string back into a date, a year, month and day are added - which I don't want. I just need to know if right now is < or > the time stored in the string.
What's going to be the best way to handle that? Thanks in advance for your help.
Instead of using the string representation, use the NSDate you got from the picker. You can convert that hour/min/sec using NSDateComponents, then also convert [NSDate date] to NSDateComponents. Compare the hours/minutes/seconds of the two sets of components.
EDIT -- use a utility function for things like this that converts the hr/min/sec components of NSDate into a secondsOfTheDay (seconds since midnight).
You can directly use two time of day values since they are both seconds since midnight. Simple integers can be easily compared and stored and manipulated. You don't have to use NSDate all the time.
//----------------------------------------------------------------------------
// extracts hour/minutes/seconds from NSDate, converts to seconds since midnight
//----------------------------------------------------------------------------
unsigned secondOfTheDay( NSDate* time )
{
NSCalendar* curCalendar = [NSCalendar currentCalendar];
const unsigned units = NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit;
NSDateComponents* comps = [curCalendar components:units fromDate:time];
int hour = [comps hour];
int min = [comps minute];
int sec = [comps second];
return ((hour * 60) + min) * 60 + sec;
}
If I understand the problem correctly, you’re using the dateFromString: method of NSDateFormatter. This is giving you the correct time, but with a default date of January 1, 1970, which is useless to compare against the current date/time.
This is easy to solve. Use setDefaultDate: to set the default date to today.
NSDate *now = [NSDate date];
NSDateFormatter *formatter = [[[NSDateFormatter alloc] init] autorelease];
[formatter setDateFormat:#"hh:mm a"];
[formatter setDefaultDate:now];
NSDate *theDate = [formatter dateFromString:#"11:13 AM"];
NSComparisonResult theResult = [theDate compare:now];
Can you reuse the string formatter that you used to create the string? So, let's say you created the string like this:
NSDateFormatter *formatter = [[[NSDateFormatter alloc] init];
[formatter setDateFormat:#"HH:mm a"];
NSString *dateAsString = [formatter stringFromDate:[NSDate date]];
You can get an NSDate like this:
NSDateFormatter *formatter = [[[NSDateFormatter alloc] init];
[formatter setDateFormat:#"HH:mm a"];
NSDate *date = [formatter dateFromString:dateAsString];
The day, month, year and timezone information will not be kept, but you'll have an NSDate object with the values of 1/1/1970 and GMT for the timezone offset.
At this point you can use the compare: (which is typically reserved for sorting operations) or the laterDate: or earlierDate: methods.
Be careful using NSDateFormatter like this, as you may run into issues with internationalization.
If you need to add information about the current date to the date you get from dateFromString:, such as the month day and year, you'll need to use NSCalendar's dateByAddingComponents:toDate:options: method.
If the string was originally created from an NSDate, then you'll want to use that original NSDate to compare against [NSDate date] using NSDate's compare: method (or some variant, such as earlierDate: or laterDate:).
You should use 24-hour based NSDateFormatter and compare as strings ("09:00am" > "08:00pm", but "09:00" < "20:00") . But in general it is right to operate with NSDate instances instead of strings