How do I compare in objective C to see if a certain time and date period overlaps another that is already in a plist for example?
This is most commonly used in booking/reservation apps to see if that particular timeslot has been taken up etc.
Try this to Compare ..
NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init];
[dateFormat setDateFormat:#"MM/dd/yyyy hh:mm:ss aa"];
NSDate *dateOne=[dateFormat dateFromString:#"01/09/2011 11:12:10 AM" ];
NSDate *dateTwo = [NSDate date];
switch ([dateOne compare:dateTwo]){
case NSOrderedAscending:
//NSLog(#"NSOrderedAscending");
break;
case NSOrderedSame:
//NSLog(#"NSOrderedSame");
{
break;
case NSOrderedDescending:
//NSLog(#"NSOrderedDescending");
break;
}
[dateFormat release];
Assuming you have the date stored as a NSDate, just use this:
[myDate timeIntervalSinceNow];
That returns a NSTimeInterval which is just a float representing the time interval in seconds. If it is negative that means that the time that you are comparing is previous.
If your date is stored in the plist as a NSString you have to convert it to a NSDate first, use a NSDateFormatter for that.
NSDateFormatter * formatter = [[NSDateFormatter alloc] init];
[formatter setDateFormat:#"yyyy-MM-dd HH:mm:ss"]; //Change this to your date format
NSDate * date = [formatter dateFromString:yourString];
[formatter release];
Related
I have a timestamp coming from server that looks like this:
2013-04-18T08:49:58.157+0000
I've tried removing the colons, I've tried all of these:
Converting an ISO 8601 timestamp into an NSDate: How does one deal with the UTC time offset?
Why NSDateFormatter can not parse date from ISO 8601 format
Here is where I am at:
+ (NSDate *)dateUsingStringFromAPI:(NSString *)dateString {
NSDateFormatter *dateFormatter;
dateFormatter = [[NSDateFormatter alloc] init];
//#"yyyy-MM-dd'T'HH:mm:ss'Z'" - doesn't work
//#"yyyy-MM-dd'T'HH:mm:ssZZZ" - doesn't work
//#"yyyy-MM-dd'T'HH:mm:sss" - doesn't work
[dateFormatter setDateFormat:#"yyyy-MM-dd'T'HH:mm:ss'Z'"];
[dateFormatter setTimeZone:[NSTimeZone timeZoneWithName:#"GMT"]];
// NSDateFormatter does not like ISO 8601 so strip the milliseconds and timezone
dateString = [dateString substringWithRange:NSMakeRange(0, [dateString length]-5)];
return [dateFormatter dateFromString:dateString];
}
One of my biggest questions is, is the date format I have above really ISO 8601? All the examples I have seen from people the formats of each are slightly different. Some have ...157-0000, others don't have anything at the end.
This works for me:
NSString *dateString = #"2013-04-18T08:49:58.157+0000";
NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
[formatter setDateFormat:#"yyyy-MM-dd'T'HH:mm:ss.SSSZ"];
// Always use this locale when parsing fixed format date strings
NSLocale *posix = [[NSLocale alloc] initWithLocaleIdentifier:#"en_US_POSIX"];
[formatter setLocale:posix];
NSDate *date = [formatter dateFromString:dateString];
NSLog(#"date = %#", date);
There is New API from Apple! NSISO8601DateFormatter
NSString *dateSTR = #"2005-06-27T21:00:00Z";
NSISO8601DateFormatter *formatter = [[NSISO8601DateFormatter alloc] init];
NSDate *date = [formatter dateFromString:dateSTR];
NSLog(#"%#", date);
I also have the native API, which is way cleaner... This is the implementation I got in my DateTimeManager class:
+ (NSDate *)getDateFromISO8601:(NSString *)strDate{
NSISO8601DateFormatter *formatter = [[NSISO8601DateFormatter alloc] init];
NSDate *date = [formatter dateFromString: strDate];
return date;
}
Just copy and paste the method, it would do the trick. Enjoy it!
The perfect and best solution that worked for me is:
let isoFormatter = ISO8601DateFormatter();
isoFormatter.formatOptions = [ISO8601DateFormatter.Options.withColonSeparatorInTime,
ISO8601DateFormatter.Options.withFractionalSeconds,
ISO8601DateFormatter.Options.withFullDate,
ISO8601DateFormatter.Options.withFullTime,
ISO8601DateFormatter.Options.withTimeZone]
let date = isoFormatter.date(from: dateStr);
For further more detail, you can refer to apple's official documentation: https://developer.apple.com/documentation/foundation/nsiso8601dateformatter
If I'm not interested in the time can I ignore it? I.e I have a date string that looks like this #"2012-12-19T14:00:00" but I'm only interested in getting the date (2012-12-19) but if I set NSDateFormatter like [dateFormatter setDateFormat:#"yyyy-MM-dd"]; it will return me a nil NSDate.
An NSDate object will always contain a time component as well, as it is representing a point in time — from this perspective one could argue the name NSDate is misleading.
You should create a date formatter for creating dates from string, set the time to the start of the day and use a second date formatter to output the date without time component.
NSString *dateString = #"2012-12-19T14:00:00";
NSDateFormatter *inputFormatter = [[NSDateFormatter alloc] init];
[inputFormatter setDateFormat:#"yyyy-MM-dd'T'HH:mm:ss"];
NSDateFormatter *outputFormatter = [[NSDateFormatter alloc] init];
[outputFormatter setDateStyle:NSDateFormatterShortStyle];
[outputFormatter setTimeStyle:NSDateFormatterNoStyle];
NSDate *date = [inputFormatter dateFromString:dateString];
//this will set date's time components to 00:00
[[NSCalendar currentCalendar] rangeOfUnit:NSDayCalendarUnit
startDate:&date
interval:NULL
forDate:date];
NSString *outputString = [outputFormatter stringFromDate:date];
NSLog(#"%#", outputString);
results in
19.12.12
while the format — as it is chosen by styling — will be dependent of your environment locale
all date string returns 10 characters for the date, what i mean is the date of todayy will be 2012-11-19
you can easily substring the date and use it as you want:
Example :
NSString* newDate = #"";
newDate = [[NSDate date]substringToIndex:10];
the out put will be : 2012-11-19
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.
hi all
I am in India.And I have used the following code to get the current date.
[NSDate date]
it displaying the "2011-01-20 06:51:35 +0000" but actual time is "2011-01-20 12:21:35 +0000"
.Please tell me how to get the current date.
Thanks in advance
You need to use Date Formatter for this purpose.Below is the sample code for that.
NSDate *testDate=[NSDate date];
NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
[formatter setDateFormat:#"MM DD YY hh:mm"];//You can set your required format here
NSString *dt = [formatter stringFromDate:testDate];
[formatter release];
NSString *strDateTaken=dt;
Cheers
What does “actual time” mean? The current time in your time zone? Considering the time values given I’d guess that the first one is GMT and you want IST (+5:30). (See Time zones on Wikipeda.) Depends on what you want to do with the date – if you just want a formatted date and time in your current time zone, Aditya’s answer should work.
To Find Current date and difference between current date and Given date...its working code
NSDate *testDate=[NSDate date];
NSDateFormatter *formatterNew = [[NSDateFormatter alloc] init];
[formatterNew setDateFormat:#"dd-MM-yyyy HH:mm:ss "];
NSString *dt = [formatterNew stringFromDate:testDate];
NSString *strDateTaken=dt;
NSLog(#"Date=%#",strDateTaken);
[formatterNew release]; // This line can be removed if you are using ARC
NSDateFormatter *tempFormatter = [[[NSDateFormatter alloc]init]autorelease];
[tempFormatter setDateFormat:#"dd-MM-yyyy HH:mm:ss"];
NSDate *toDate = [tempFormatter dateFromString:strDateTaken];
NSLog(#"Current Date ==%#",toDate);
NSDateFormatter *tempFormatter1 = [[[NSDateFormatter alloc]init]autorelease];
[tempFormatter1 setDateFormat:#"dd-MM-yyyy HH:mm:ss"];
NSDate *startdate = [tempFormatter1 dateFromString:#"30-08-2011 16:25:00"];
NSLog(#"Last Date ==%#",startdate);
int i = [startdate timeIntervalSince1970];
int j = [toDate timeIntervalSince1970];
double X = j-i;
int days=(int)((double)X/(3600.0*24.00));
NSLog(#" Difference :%d",days);
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