Objective-C NSDate Utils.

NSDate+Utils.h

//
//  NSDate+Utils.h
//
//  Copyright (c) 2015 Yuta Takahashi
//
//  Permission is hereby granted, free of charge, to any person obtaining a copy
//  of this software and associated documentation files (the "Software"), to deal
//  in the Software without restriction, including without limitation the rights
//  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
//  copies of the Software, and to permit persons to whom the Software is
//  furnished to do so, subject to the following conditions:
//
//  The above copyright notice and this permission notice shall be included in
//  all copies or substantial portions of the Software.
//
//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
//  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
//  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
//  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
//  THE SOFTWARE.
//

#import <Foundation/Foundation.h>

@interface NSDate (Utils)

+ (NSDate *)ytg_localTime;

/**
 *  基本形式ISO8601を文字列として返す
 *
 *  @return ex)20150701T035640+0900
 */
+ (NSString *)ytg_basicISO8601String;

/**
 *  拡張形式ISO8601を文字列として返す
 *
 *  @return ex)2015-07-01T03:56:40+09:00
 */
+ (NSString *)ytg_extendedISO8601String;

/**
 *  基本形式ISO8601をNSDate(GMT)に変換する
 *
 *  @param dateString ex)20150701T035640+0900
 *
 *  @return ex)2015-06-30 18:56:40 +0000
 */
+ (NSDate *)ytg_basicISO8601:(NSString *)dateString;

/**
 *  拡張形式ISO8601をNSDate(GMT)に変換する
 *
 *  @param dateString ex)2015-07-01T03:56:40+09:00
 *
 *  @return ex)2015-06-30 18:56:40 +0000
 */
+ (NSDate *)ytg_extendedISO8601:(NSString *)dateString;

@end

NSDate+Utils.m

//
//  NSDate+Utils.m
//

#import "NSDate+Utils.h"

@implementation NSDate (Utils)

+ (NSDate *)ytg_localTime {
    NSDate *date = [NSDate date];
    NSTimeZone *timeZone = [NSTimeZone localTimeZone];
    NSInteger seconds = [timeZone secondsFromGMTForDate:date];
    return [NSDate dateWithTimeInterval:seconds sinceDate:date];
}

+ (NSString *)ytg_basicISO8601String {
    NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
    NSLocale *locale = [NSLocale localeWithLocaleIdentifier:@"en_US_POSIX"];
    [dateFormatter setLocale:locale];
    [dateFormatter setDateFormat:@"yyyyMMdd'T'HHmmssZ"];
    return [dateFormatter stringFromDate:[NSDate date]];
}

+ (NSString *)ytg_extendedISO8601String {
    NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
    NSLocale *locale = [NSLocale localeWithLocaleIdentifier:@"en_US_POSIX"];
    [dateFormatter setLocale:locale];
    [dateFormatter setDateFormat:@"yyyy-MM-dd'T'HH:mm:ssZZZZZ"];
    return [dateFormatter stringFromDate:[NSDate date]];
}

+ (NSDate *)ytg_basicISO8601:(NSString *)dateString {
    NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
    [formatter setDateFormat:@"yyyyMMdd'T'HHmmssZ"];
    NSLocale *locale = [[NSLocale alloc] initWithLocaleIdentifier:@"en_US_POSIX"];
    [formatter setLocale:locale];
    return [formatter dateFromString:dateString];
}

+ (NSDate *)ytg_extendedISO8601:(NSString *)dateString {
    NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
    [formatter setDateFormat:@"yyyy-MM-dd'T'HH:mm:ssZZZZZ"];
    NSLocale *locale = [[NSLocale alloc] initWithLocaleIdentifier:@"en_US_POSIX"];
    [formatter setLocale:locale];
    return [formatter dateFromString:dateString];
}

@end

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