NSDateFormatter setDateFormat example objc

[NSDateFormatter setDateFormat] is used to specify how to generate NSString object from the given NSDate object. [NSDateFormatter setDateFormat] takes a format specifier which has its own rules. You can find out more information on iPhone developer site. http://developer.apple.com/library/mac/#documentation/Cocoa/Conceptual/DataFormatting/Articles/dfDateFormatting10_4.html#//apple_ref/doc/uid/TP40002369-SW1
[NSDateFormatter setDateFormat example]

Declaration.

- (void)setDateFormat:(NSString *)string

Parameters

string

The date format for the receiver. See Data Formatting Guide for a list of the conversion specifiers permitted in date format strings.

------------------------------------------------------------------------
[Example 1]

NSDate *today = [NSDate date];
NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init];
[dateFormat setDateFormat:@"MM/dd/yyyy :EEEE"];
NSString *dateString = [dateFormat stringFromDate:today];
NSLog(@"date: %@", dateString);
[dateFormat release];
NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
NSDateComponents *components = [gregorian components:NSWeekdayCalendarUnit | NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit fromDate:today];
[components setDay:([components day]-([components weekday]-1))];
NSDate *beginningOfWeek = [gregorian dateFromComponents:components];
NSDateFormatter *dateFormat_first = [[NSDateFormatter alloc] init];
[dateFormat_first setDateFormat:@"MM/dd/yyyy :EEEE"];
NSString *dateString_first = [dateFormat_first stringFromDate:beginningOfWeek];
NSLog(@"First_date: %@", dateString_first);

--------------------------------------------------------------------

[Example 2 from Apple Developer Site]

// Formatting a date using formatter styles

NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];

[dateFormatter setDateStyle:NSDateFormatterMediumStyle];

[dateFormatter setTimeStyle:NSDateFormatterNoStyle];

NSDate *date = [NSDate dateWithTimeIntervalSinceReferenceDate:162000];

NSString *formattedDateString = [dateFormatter stringFromDate:date];

NSLog(@"formattedDateString: %@", formattedDateString);

// Output for locale en_US: "formattedDateString: Jan 2, 2001"

--------------------------------------------------------------------- 

[Example 3 from Apple Developer Site]

NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];

[dateFormatter setDateFormat:@"yyyy-MM-dd 'at' HH:mm"];

NSDate *date = [NSDate dateWithTimeIntervalSinceReferenceDate:162000];

NSString *formattedDateString = [dateFormatter stringFromDate:date];

NSLog(@"formattedDateString: %@", formattedDateString);

// For US English, the output may be:

// formattedDateString: 2001-01-02 at 13:00

--------------------------------------------------------------------- 
[Example 4 from Apple Developer Site]

NSString *formatString = [NSDateFormatter dateFormatFromTemplate:@"EdMMM" options:0

locale:[NSLocale currentLocale]];

NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];

[dateFormatter setDateFormat:formatString];

NSString *todayString = [dateFormatter stringFromDate:[NSDate date]];

NSLog(@"todayString: %@", todayString);

 

--------------------------------------------------------------------- 
[Example 5 from Apple Developer Site]

NSLocale *usLocale = [[NSLocale alloc] initWithLocaleIdentifier:@"en_US"];

NSString *usFormatString = [NSDateFormatter dateFormatFromTemplate:@"EdMMM" options:0 locale:usLocale];

NSLog(@"usFormatterString: %@", usFormatString);

// Output: usFormatterString: EEE, MMM d

NSLocale *gbLocale = [[NSLocale alloc] initWithLocaleIdentifier:@"en_GB"];

NSString *gbFormatString = [NSDateFormatter dateFormatFromTemplate:@"EdMMM" options:0 locale:gbLocale];

NSLog(@"gbFormatterString: %@", gbFormatString);

// Output: gbFormatterString: EEE d MMM

--------------------------------------------------------------------- 
[Example 6 from Apple Developer Site]

- (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.

{

NSString * userVisibleDateTimeString;

NSDateFormatter * rfc3339DateFormatter;

NSLocale * enUSPOSIXLocale;

NSDate * date;

NSDateFormatter * userVisibleDateFormatter;

userVisibleDateTimeString = nil;

// Convert the RFC 3339 date time string to an NSDate.

rfc3339DateFormatter = [[[NSDateFormatter alloc] init] autorelease];

enUSPOSIXLocale = [[[NSLocale alloc] initWithLocaleIdentifier:@"en_US_POSIX"] autorelease];

[rfc3339DateFormatter setLocale:enUSPOSIXLocale];

[rfc3339DateFormatter setDateFormat:@"yyyy'-'MM'-'dd'T'HH':'mm':'ss'Z'"];

[rfc3339DateFormatter setTimeZone:[NSTimeZone timeZoneForSecondsFromGMT:0]];

date = [rfc3339DateFormatter dateFromString:rfc3339DateTimeString];

if (date != nil) {

// Convert the NSDate to a user-visible date string.

userVisibleDateFormatter = [[[NSDateFormatter alloc] init] autorelease];

assert(userVisibleDateFormatter != nil);

[userVisibleDateFormatter setDateStyle:NSDateFormatterShortStyle];

[userVisibleDateFormatter setTimeStyle:NSDateFormatterShortStyle];

userVisibleDateTimeString = [userVisibleDateFormatter stringFromDate:date];

}

return userVisibleDateTimeString;

}