`YYYY` is not the same as `yyyy`.

According to [this page](https://unicode.org/reports/tr35/tr35-10.html#Date_Format_Patterns) which the [iOS Date format page](https://developer.apple.com/library/archive/documentation/Cocoa/Conceptual/DataFormatting/Articles/dfDateFormatting10_4.html) references;

    `y`: Year
    `Y`: Year (in &quot;Week of Year&quot; based calendars). This year designation is used in 
         ISO year-week calendar as defined by ISO 8601, but can be used in 
         non-Gregorian based calendar systems where week date processing is desired. 
         May not always be the same value as calendar year.

The operative sentence being the last one. Use `yyyy`instead.


---
Further details on how and why the year values may deviate when using `YYYY`:

&gt; The ISO week-numbering year starts at the first day (Monday) of week
&gt; 01 and ends at the Sunday before the new ISO year (hence without
&gt; overlap or gap). It consists of 52 or 53 **full weeks**. The ISO
&gt; week-numbering year number deviates from the number of the traditional
&gt; Gregorian calendar year on a Friday, Saturday, and Sunday, or a
&gt; Saturday and Sunday, or just a Sunday, at the start of the traditional
&gt; Gregorian calendar year (which are at the end of the previous ISO
&gt; week-numbering year) and a Monday, Tuesday and Wednesday, or a Monday
&gt; and Tuesday, or just a Monday, at the end of the traditional Gregorian
&gt; calendar year (which are in week 01 of the next ISO week-numbering
&gt; year). For Thursdays, the ISO week-numbering year number is always
&gt; equal to the traditional Gregorian calendar year number.
&gt; 
&gt; Examples:
&gt; 
&gt; Monday 29 December **2008** is written &quot;**2009**-W01-1&quot; 
&gt;
&gt; Sunday 3 January **2010** is written &quot;**2009**-W53-7&quot;

From https://en.wikipedia.org/wiki/ISO_8601#Week_dates
*(bold styling added)*


I currently use NLog on a lot of projects. On some, I log to a database. 

Here is what I would like to do:

    CREATE TABLE [dbo].[NLogEntries](
  	  [Id] [bigint] IDENTITY(1,1) NOT NULL,
	  [Origin] [nvarchar](100) NOT NULL,
	  [LogLevel] [nvarchar](20) NOT NULL,
	  [Message] [nvarchar](3600) NOT NULL,
	  [CreatedOn] [datetime] NOT NULL,
	  [OrderId] [int] NULL --Custom field!
    )

And NLog.config with this target:

&lt;!-- language: xml --&gt;

    &lt;target type=&quot;Database&quot; name=&quot;database&quot; connectionstring=&quot;Server=localhost;Database=NLog;Trusted_Connection=True;&quot;&gt;
      &lt;commandText&gt;
        INSERT INTO NLogEntries ([Origin], [Message], [LogLevel],[CreatedOn],[OrderId]) VALUES (@Origin,@Message,@LogLevel,@Date, @OrderId);
      &lt;/commandText&gt;
      &lt;parameter name=&quot;@Date&quot; layout=&quot;${date}&quot;/&gt;
      &lt;parameter name=&quot;@Origin&quot; layout=&quot;${callsite}&quot;/&gt;
      &lt;parameter name=&quot;@LogLevel&quot; layout=&quot;${level}&quot;/&gt;
      &lt;parameter name=&quot;@message&quot; layout=&quot;${message}&quot;/&gt;
      &lt;parameter name=&quot;@OrderId&quot; layout=&quot;${orderId}&quot;/&gt; &lt;!-- custom field! --&gt;
    &lt;/target&gt;

And then log something like this:

    var logger = LogManager.GetCurrentClassLogger();
    var orderId = 123;
    logger.Debug(&quot;What is going on here&quot;, orderId);

Is there a good way to do this and keep using NLog? Or do I have to roll my own logger and skip NLog when these are the requirements?

How do I log a custom field in NLog to database?

Is there any shortcut for maximizing the tab you are working on in Eclipse? Assume I am working on part of a code and I want to maximize the tab not using the double click on it with the mouse, does anyone know a way? 

Maximize code tab in eclipse shortcut

im using xcode 4.5(4G182) with iOS 6. NSDateFormatter show wrong year in iOS 6, how to solve?

    NSDateFormatter *dateFormatter = [[[NSDateFormatter alloc] init] autorelease];
    [dateFormatter setDateFormat:@&quot;YYYY-MM-dd&quot;];
    NSString *str = [dateFormatter stringFromDate:[NSDate date]];
    NSLog(@&quot;%@ == %@&quot;,str,[[dateFormatter dateFromString:str] description]);

it print out &quot;**2012**-09-14 == **2011**-09-13 16:00:00 +0000&quot;

NSDateFormatter show wrong year

im using xcode 4.5(4G182) with iOS 6. NSDateFormatter show wrong year in iOS 6, how to solve?
<pre><code class="hljs language-ini">NSDateFormatter *dateFormatter = [[[NSDateFormatter alloc] init] autorelease];
[dateFormatter setDateFormat:@"YYYY-MM-dd"];
NSString *str = [dateFormatter stringFromDate:[NSDate date]];
NSLog(@"%@ == %@",str,[[dateFormatter dateFromString:str] description]);
</code></pre>
it print out "2012-09-14 == 2011-09-13 16:00:00 +0000"

I have some code I use to sort calendar dates that looks like this: 

    #if !(TARGET_IPHONE_SIMULATOR)
        NSString *formatString = [NSDateFormatter dateFormatFromTemplate:@&quot;HH:mm dd MMM yyyy&quot; options:0
                                                                  locale:[NSLocale currentLocale]];
        [fmt setDateFormat:formatString];
    #else
        [fmt setDateFormat:@&quot;HH:mm dd MMM yyyy&quot;];
    #endif

If I run it in the simulator all is ok. If I run it on the device I get this sarcastic debug message. 

&gt; **2012-09-19 22:40:13.972 APPNAME [4923:907] *** -[__NSCFCalendar
&gt; components:fromDate:]: date cannot be nil 

&gt; I mean really, what do you
&gt; think that operation is supposed to mean with a nil date?
&gt; 
&gt;  An exception has been avoided for now.
&gt; 
&gt; A few of these errors are going to be
&gt; reported with this complaint, then further violations will simply
&gt; silently do whatever random thing results from the nil. Here is the
&gt; backtrace where this occurred this time (some frames may be missing
&gt; due to compiler optimizations):

You have to laugh at it but I&#39;m not sure what is wrong with my `dateFormatFromTemplate:` code. Any help would be appreciated. 

*Running Xcode V 4.5 btw* 

________
UPDATE:

&gt; Backtrace:
&gt; 
&gt; 	0   CoreFoundation                      0x39ff0e55 &lt;redacted&gt; + 84 	
   1
&gt; APPNAME                             0x00040be1
&gt; -[MeetingsViewController dateAtBeginningOfDayForDate:] + 140

So I guess things are going bad in my `dateAtBeginningOfDayForDate` method. Which looks like this:

    /*
     Break down a given NSDate to its bare components for sorting
     */
    - (NSDate *)dateAtBeginningOfDayForDate:(NSDate *)inputDate
    {
        // Use the user&#39;s current calendar and time zone
        NSCalendar *calendar = [NSCalendar currentCalendar];
        NSTimeZone *timeZone = [NSTimeZone systemTimeZone];
        [calendar setTimeZone:timeZone];
        
        // Selectively convert the date components (year, month, day) of the input date
        NSDateComponents *dateComps = [calendar components:NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit fromDate:inputDate];
        
        // Set the time components manually
        [dateComps setHour:0];
        [dateComps setMinute:0];
        [dateComps setSecond:0];
        
        // Convert back
        NSDate *beginningOfDay = [calendar dateFromComponents:dateComps];
        return beginningOfDay;
    }

I use this method to break down a given NSDate to its&#39; core components so that I can sort them all more efficiently. However, my app has to be international which is the reason behind using `NSLocale` to formate the date output. From what it seems I will need to alter my `dateAtBeginningOfDayForDate` to work internationally as well. 

What kind of sarcastic error is this iOS?

What is exact difference between &#39;YYYY&#39; and &#39;yyyy&#39;. I read in [this link][1], it states that 

&gt; A common mistake is to use YYYY. yyyy specifies the calendar year
&gt; whereas YYYY specifies the year (of “Week of Year”), used in the ISO
&gt; year-week calendar. In most cases, yyyy and YYYY yield the same
&gt; number, however they may be different. Typically you should use the
&gt; calendar year.

But when I try to use 

    NSString *stringDate = @&quot;Feb 28, 2013 05:30pm&quot;;
    NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
    [dateFormatter setDateFormat:@&quot;MMM dd, yyyy hh:mma&quot;];
    NSDate *date=[dateFormatter dateFromString:stringDate];
    NSLog(@&quot;Date 1 : %@&quot;,date); //2013-02-28 12:00:00 +0000
    
    NSString *stringDatee = @&quot;Feb 28, 2013 05:30pm&quot;;
    NSDateFormatter *dateFormatterr = [[NSDateFormatter alloc] init];
    [dateFormatterr setDateFormat:@&quot;MMM dd, YYYY hh:mma&quot;];
    NSDate *datee=[dateFormatterr dateFromString:stringDatee];
    NSLog(@&quot;Date 2 : %@&quot;,datee); //2013-01-05 12:00:00 +0000
    
    NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init];
    [dateFormat setDateFormat:@&quot;MMM dd, YYYY hh:mma&quot;];
    NSString *dateString = [dateFormat stringFromDate:datee];
    NSLog(@&quot;date 3 : %@&quot;, dateString); //Jan 05, 2013 05:30PM

As here, result to `date` and `datee` different, which I understood, but why result of date 2 and date 3 are different? As I am creating date from string and reversing same to string again, but output mismatches?

Has anybody knows reason about same?. Though it specifies week of year, still I should get result same.

Thanks..

EDIT :-

If I code

    NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init];
    [dateFormat setDateFormat:@&quot;MMM dd, YYYY hh:mma&quot;];
    NSString *dateString = [dateFormatterr stringFromDate:[NSDate date]];
    NSLog(@&quot;date: %@&quot;, dateString); //Feb 28, 2013 04:37PM

If results me proper result, but same which I pass as string to date I get `2013-01-05 12:00:00 +0000`, check date 2 of NSLog, Strange result, why?

  [1]: https://developer.apple.com/library/mac/#documentation/Cocoa/Conceptual/DataFormatting/Articles/dfDateFormatting10_4.html#//apple_ref/doc/uid/TP40002369-SW1

Difference between &#39;YYYY&#39; and &#39;yyyy&#39; in NSDateFormatter

It&#39;s easy enough to get the ISO 8601 date string (for example, `2004-02-12T15:19:21+00:00`) in PHP via `date(&#39;c&#39;)`, but how does one get it in Objective-C (iPhone)? Is there a similarly short way to do it?

Here&#39;s the *long* way I found to do it:

    NSDateFormatter* dateFormatter = [[[NSDateFormatter alloc] init] autorelease];
    dateFormatter.dateFormat = @&quot;yyyy-MM-dd&#39;T&#39;HH:mm:ssZ&quot;;

    NSDate *now = [NSDate date];
    NSString *formattedDateString = [dateFormatter stringFromDate:now];
    NSLog(@&quot;ISO-8601 date: %@&quot;, formattedDateString);

    // Output: ISO-8601 date: 2013-04-27T13:27:50-0700

It seems an awful lot of rigmarole for something so central.



How do I get an ISO 8601 date on iOS?

I have a basic method which gets the current time and sets it in a string. However, how can I get it to format the current date &amp; time in a UNIX since-1970 timestamp format?

Here is my code:

    NSDate *currentTime = [NSDate date];
    NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
    [dateFormatter setDateFormat:@&quot;hh-mm&quot;];
    NSString *resultString = [dateFormatter stringFromDate: currentTime];

Is it possible to use `NSDateFormatter` to change the &#39;resultString&#39; into a timestamp?

Get current NSDate in timestamp format

I am trying to convert an am/pm format time to a 24 hour format time

    6:35 PM to 18:35

I tried this piece of code on playground but it doesn&#39;t seem to
work if I put the time alone

    let dateAsString = &quot;02/12/15, 6:35 PM&quot;
    let dateFormatter = NSDateFormatter()
    dateFormatter.dateFormat = &quot;HH&quot;
    let date = dateFormatter.dateFromString(dateAsString) //returns nil


Does anyone know how to accomplish this?

Xcode Swift am/pm time to 24 hour format

I&#39;ve just upgraded to XCode 4.5 to update my iOS app to run on the 4 inch display for the iPhone 5, but I&#39;m getting a build error saying `dismissModalViewControllerAnimated:&#39; is deprecated` on the line:

    [self dismissModalViewControllerAnimated:NO];

I&#39;ve tried updating to the recommended overload with a completion handler (but set to NULL) like this:

    [self dismissModalViewControllerAnimated:NO completion:NULL];

But then this line throws two errors:

    warning: &#39;TabBarController&#39; may not respond to &#39;-presentModalViewController:animated:completion:&#39;
    Instance method &#39;-presentModalViewController:animated:completion:&#39; not found (return type defaults to &#39;id&#39;)

Thanks!

dismissModalViewControllerAnimated deprecated

In my app I have multiple views, some views need to support both portrait and landscape, while other views need to support portrait only.  Thus, in the project summary, I have all selected all orientations.

The below code worked to disable landscape mode on a given view controller prior to iOS 6:

    - (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
    {
        // Return YES for supported orientations
        return (interfaceOrientation == UIInterfaceOrientationPortrait);
    }

Since shouldAutorotateToInterfaceOrientation was deprecated in iOS6 I&#39;ve replaced the above with:

    -(NSUInteger)supportedInterfaceOrientations{
        return UIInterfaceOrientationMask.Portrait;
    }


This method is correctly called when the view appears (I can set a breakpoint to ensure this), but the interface still rotates to landscape mode regardless of the fact that I&#39;m returning the mask for portrait modes only.  What am I doing wrong?

It seems that it&#39;s currently impossible to build an app that has different orientation requirements per view.  It seems to only adhere to the orientations specified in the project summary.

iOS6: supportedInterfaceOrientations not working (is invoked but the interface still rotates)

Just curious, as it doesn&#39;t immediately seem possible, but is there a sneaky way to leverage the new iOS 6 `UIRefreshControl` class without using a `UITableViewController` subclass?

I often use a `UIViewController` with a `UITableView` subview and conform to `UITableViewDataSource` and `UITableViewDelegate` rather than using a `UITableViewController` outright.

UIRefreshControl without UITableViewController

What are the steps I need to follow to use iOS 6&#39;s new `SLComposeViewController` to post to Facebook, Twitter or Sina Weibo?


Tutorial for SLComposeViewController sharing

Previous to iOS 6, opening a URL like this would open the (Google) Maps app:

    NSURL *url = [NSURL URLWithString:@&quot;http://maps.google.com/?q=New+York&quot;];
    [[UIApplication sharedApplication] openURL:url];

Now with the new Apple Maps implementation, this just opens Mobile Safari to Google Maps. How can I accomplish the same behavior with iOS 6? How do I programmatically open the Maps app and have it point to a specific location/address/search/whatever?

Content Type	Original Author	Original Content on Stackoverflow
Question	Simon	View Question on Stackoverflow
Solution 1 - Nsdateformatter	Joachim Isaksson	View Answer on Stackoverflow

NSDateFormatter show wrong year

Nsdateformatter Problem Overview

Nsdateformatter Solutions

Solution 1 - Nsdateformatter

Maximize code tab in eclipse shortcut

How do I log a custom field in NLog to database?

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