how to use NSDateFormatter for different format?

 Hi,
Using the below category for NSDate, you can use below functions to get various date format string or date.

 #import <Foundation/Foundation.h>

@interface NSDate(TCUtils)
- (NSDate *)TC_dateByAddingCalendarUnits:(NSCalendarUnit)calendarUnit amount:(NSInteger)amount;
- (NSString*)TC_dateindisplayformat:(NSString*) format;
- (NSString*)TC_datewithTformat:(NSString*)dt format:(NSString*) format;
- (NSString*)TC_dateformat:(NSString*)dt format:(NSString*) format;
- (NSDate*)TC_stringformat:(NSString*)dt format:(NSString*) format;
- (NSString*)TC_date24format:(NSString*)dt format:(NSString*) format;
- (NSDate*)TC_datewithTformat:(NSString*)dt;
- (BOOL)isSameDay:(NSDate*)anotherDate;
- (NSDate *) todayDateWithoutTime;
@end



#import "NSDate+TCUtils.h"

@implementation NSDate (TCUtils)

- (NSDate *)TC_dateByAddingCalendarUnits:(NSCalendarUnit)calendarUnit amount:(NSInteger)amount {
    NSDateComponents *components = [[NSDateComponents alloc] init];
    NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
    NSDate *newDate;
   
    switch (calendarUnit) {
        case NSSecondCalendarUnit:
            [components setSecond:amount];
            break;
        case NSMinuteCalendarUnit:
            [components setMinute:amount];
            break;
        case NSHourCalendarUnit:
            [components setHour:amount];
            break;
        case NSDayCalendarUnit:
            [components setDay:amount];
            break;
        case NSWeekCalendarUnit:
            [components setWeek:amount];
            break;
        case NSMonthCalendarUnit:
            [components setMonth:amount];
            break;
        case NSYearCalendarUnit:
            [components setYear:amount];
            break;
        default:
            ////NSLog(@"addCalendar does not support that calendarUnit!");
            break;
    }
   
    newDate = [gregorian dateByAddingComponents:components toDate:self options:0];
    [components release];
    [gregorian release];
    return newDate;
}

- (NSString*)TC_dateindisplayformat:(NSString*) format
{
    NSDateFormatter* df=[[[NSDateFormatter alloc] init] autorelease];
    [df setTimeZone:[NSTimeZone defaultTimeZone]];
    NSLocale *locale = [[[NSLocale alloc]
                         initWithLocaleIdentifier:@"en_US_POSIX"] autorelease]; 
    [df setLocale:locale];
    [df setDateFormat:format];
    return [df stringFromDate:self];   
}

- (NSString*)TC_datewithTformat:(NSString*)dt format:(NSString*) format
{
    NSDateFormatter* df=[[[NSDateFormatter alloc] init] autorelease];
    [df setTimeZone:[NSTimeZone defaultTimeZone]];
    NSLocale *locale = [[[NSLocale alloc]
                         initWithLocaleIdentifier:@"en_US_POSIX"] autorelease]; 
    [df setLocale:locale];
    [df setDateFormat:@"yyyy-MM-dd"];
    NSArray* a=[dt componentsSeparatedByString:@"T"];
    NSDate* tdt;
    if([a count]>0){
        tdt=[df dateFromString:[a objectAtIndex:0]];
    }
    else{
        tdt=[NSDate date];
    }
    [df setDateFormat:format];
   
    return [df stringFromDate:tdt];
}

- (NSString*)TC_dateformat:(NSString*)dt format:(NSString*) format
{
    NSDateFormatter* df=[[[NSDateFormatter alloc] init] autorelease];
    [df setTimeZone:[NSTimeZone defaultTimeZone]];
    NSLocale *locale = [[[NSLocale alloc]
                         initWithLocaleIdentifier:@"en_US_POSIX"] autorelease]; 
    [df setLocale:locale];
    [df setDateFormat:@"yyyy-MM-dd"];
    NSDate* tdt=[df dateFromString:dt];
    [df setDateFormat:format];
   
    return [df stringFromDate:tdt];
}

- (NSDate*)TC_stringformat:(NSString*)dt format:(NSString*) format
{
    NSDateFormatter* df=[[[NSDateFormatter alloc] init] autorelease];
    [df setTimeZone:[NSTimeZone defaultTimeZone]];
    NSLocale *locale = [[[NSLocale alloc]
                         initWithLocaleIdentifier:@"en_US_POSIX"] autorelease]; 
    [df setLocale:locale];
    [df setDateFormat:format];

    return [df dateFromString:dt];
}

- (NSDate*)TC_datewithTformat:(NSString*)dt
{
    NSDateFormatter* df=[[[NSDateFormatter alloc] init] autorelease];
    [df setTimeZone:[NSTimeZone defaultTimeZone]];
    NSLocale *locale = [[[NSLocale alloc]
                         initWithLocaleIdentifier:@"en_US_POSIX"] autorelease];
    [df setLocale:locale];
    dt=[dt stringByReplacingOccurrencesOfString:@"T" withString:@" "];
    [df setDateFormat:@"yyyy-MM-dd HH:mm:ss"];
    return [df dateFromString:dt];
}

- (NSString*)TC_date24format:(NSString*)dt format:(NSString*) format
{
    NSDateFormatter* df=[[[NSDateFormatter alloc] init] autorelease];
    [df setTimeZone:[NSTimeZone defaultTimeZone]];
    NSLocale *locale = [[[NSLocale alloc]
                         initWithLocaleIdentifier:@"en_US_POSIX"] autorelease]; 
    [df setLocale:locale];
    [df setDateFormat:@"yyyy-MM-dd hh:mm a"];
    NSDate* tdt=[df dateFromString:dt];
    [df setDateFormat:format];
   
    return [df stringFromDate:tdt];
}

- (NSDate *) todayDateWithoutTime
{
    NSDateFormatter *df = [[[NSDateFormatter alloc] init] autorelease];
      [df setTimeZone:[NSTimeZone  defaultTimeZone]];
    NSLocale *locale = [[[NSLocale alloc]
                         initWithLocaleIdentifier:@"en_US_POSIX"] autorelease];
    [df setLocale:locale];
    [df setDateFormat:@"yyyy-MM-dd"];

    NSString *todayDateS = [df stringFromDate:[NSDate date]];
    NSDate *todayDate = [df dateFromString:todayDateS];
    return todayDate;
}



- (BOOL)isSameDay:(NSDate*)anotherDate{
    NSCalendar* calendar = [NSCalendar currentCalendar];
    NSDateComponents* components1 = [calendar components:(NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit) fromDate:self];
    NSDateComponents* components2 = [calendar components:(NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit) fromDate:anotherDate];
    return ([components1 year] == [components2 year] && [components1 month] == [components2 month] && [components1 day] == [components2 day]);
}

@end

NSDateFormatter Example in iPhone SDK

Hi,
Every one,
I'm going to share NSDateFormatter examples for iPhone/iPad Applications. Please check below code reference :

+(NSString *)returnDateString:(NSDate *)date
{
    NSDateFormatter *formatter = [[[NSDateFormatter alloc] init] autorelease];
    [formatter setFormatterBehavior:NSDateFormatterBehavior10_4];
    [formatter setDateFormat:@"dd/MM/yyyy"];
    NSLocale *usLocale = [NSLocale systemLocale];
    [formatter setLocale:usLocale];
    usLocale = nil;
    return [formatter stringFromDate:date];
}

+(NSString *)returnDateStringWithTime:(NSDate *)date
{
    NSDateFormatter *formatter = [[[NSDateFormatter alloc] init] autorelease];
    [formatter setFormatterBehavior:NSDateFormatterBehavior10_4];
    [formatter setDateFormat:@"yyyy-MM-dd HH:mm:ss"];
    NSLocale *usLocale = [NSLocale systemLocale];
    [formatter setLocale:usLocale];
    usLocale = nil;
    return [formatter stringFromDate:date];
}

+(NSDate *)returnFormattedStringWithDate:(NSString *)dateString
{
    NSDateFormatter *dateFormatter = [[[NSDateFormatter alloc] init] autorelease];
    [dateFormatter setFormatterBehavior:NSDateFormatterBehavior10_4];
    [dateFormatter setDateFormat:@"yyyy-MM-dd HH:mm:ss"];
       NSLocale *usLocale = [NSLocale systemLocale];
    [dateFormatter setLocale:usLocale];
    usLocale = nil;
    return [dateFormatter dateFromString:dateString];
}

Here is the list of the string formats that can be used with NSDateFormatter in iPhone/iPad Applications.

a: AM/PM
A: 0~86399999 (Millisecond of Day)

c/cc: 1~7 (Day of Week)
ccc: Sun/Mon/Tue/Wed/Thu/Fri/Sat
cccc: Sunday/Monday/Tuesday/Wednesday/Thursday/Friday/Saturday

d: 1~31 (0 padded Day of Month)
D: 1~366 (0 padded Day of Year)

e: 1~7 (0 padded Day of Week)
E~EEE: Sun/Mon/Tue/Wed/Thu/Fri/Sat
EEEE: Sunday/Monday/Tuesday/Wednesday/Thursday/Friday/Saturday

F: 1~5 (0 padded Week of Month, first day of week = Monday)

g: Julian Day Number (number of days since 4713 BC January 1)
G~GGG: BC/AD (Era Designator Abbreviated)
GGGG: Before Christ/Anno Domini

h: 1~12 (0 padded Hour (12hr))
H: 0~23 (0 padded Hour (24hr))

k: 1~24 (0 padded Hour (24hr)
K: 0~11 (0 padded Hour (12hr))

L/LL: 1~12 (0 padded Month)
LLL: Jan/Feb/Mar/Apr/May/Jun/Jul/Aug/Sep/Oct/Nov/Dec
LLLL: January/February/March/April/May/June/July/August/September/October/November/December

m: 0~59 (0 padded Minute)
M/MM: 1~12 (0 padded Month)
MMM: Jan/Feb/Mar/Apr/May/Jun/Jul/Aug/Sep/Oct/Nov/Dec
MMMM: January/February/March/April/May/June/July/August/September/October/November/December

q/qq: 1~4 (0 padded Quarter)
qqq: Q1/Q2/Q3/Q4
qqqq: 1st quarter/2nd quarter/3rd quarter/4th quarter
Q/QQ: 1~4 (0 padded Quarter)
QQQ: Q1/Q2/Q3/Q4
QQQQ: 1st quarter/2nd quarter/3rd quarter/4th quarter

s: 0~59 (0 padded Second)
S: (rounded Sub-Second)

u: (0 padded Year)

v~vvv: (General GMT Timezone Abbreviation)
vvvv: (General GMT Timezone Name)

w: 1~53 (0 padded Week of Year, 1st day of week = Sunday, NB: 1st week of year starts from the last Sunday of last year)
W: 1~5 (0 padded Week of Month, 1st day of week = Sunday)

y/yyyy: (Full Year)
yy/yyy: (2 Digits Year)
Y/YYYY: (Full Year, starting from the Sunday of the 1st week of year)
YY/YYY: (2 Digits Year, starting from the Sunday of the 1st week of year)

z~zzz: (Specific GMT Timezone Abbreviation)
zzzz: (Specific GMT Timezone Name)
Z: +0000 (RFC 822 Timezone)


Thanks & Regards,
Nilesh Prajapati