NSDate 日期操作工具類

    //

    //  main.m

    //  OC05-task-06

    //

    //  Created by Xin the Great on 15-1-26.

    //  Copyright (c) 2015年 Xin the Great. All rights reserved.

    //


#import <Foundation/Foundation.h>  

int main(int argc, const charchar * argv[]) {  
    @autoreleasepool {  
        // insert code here...  
        //////////////////////NSDate --- 日期//////////////////////  

        //獲取當前系統的時間   標準時間 GMT  格林尼治時間  
        NSDate *date = [NSDate date];  
        NSLog(@"date is %@", date);  

        NSDate *date1 = [[NSDate alloc] init];  
        NSLog(@"date1 is %@", date1);  

        //獲取時間戳   以秒為單位  
        NSTimeInterval time1970 = [date timeIntervalSince1970];  
        NSLog(@"time1970 is %.1f", time1970);  

        NSTimeInterval time2001 = [date timeIntervalSinceReferenceDate];  
        NSLog(@"time2001 is %.1f", time2001);  

        NSTimeInterval time = [date timeIntervalSinceNow];  
        NSLog(@"time is %.1f", time);  

        //獲取昨天的時間  
        NSTimeInterval second = 224 * 660 * 60;  
        NSDate *yesterDayDate = [[NSDate alloc] initWithTimeIntervalSinceNow:-second];  
        NSLog(@"yesterDayDate is %@",yesterDayDate);  

        //獲取明天的時間  
        NSDate *tomorrowDayDate = [NSDate dateWithTimeInterval:second sinceDate:[NSDate date]];  
        NSLog(@"tomorrowDayDate is %@", tomorrowDayDate);  

        //獲得未來的某一個時間  
        NSDate *future = [NSDate distantFuture];  
        NSLog(@"future is %@", future);  

        //獲得古代的某一個時間  
        NSDate *past = [NSDate distantPast];  
        NSLog(@"past is %@", past);  

        //日期的比較  
//        BOOL isTure = [date isEqualToDate:date1];  
//        NSLog(@"isTure is %d", isTure);  

        //返回兩個時間比較早的那個時間  
        NSDate *earlierDate = [tomorrowDayDate earlierDate:future];  
        NSLog(@"earlierDate is %@", earlierDate);  

        //返回兩個時間比較晚的那個時間  
        NSDate *later = [tomorrowDayDate laterDate:future];  
        NSLog(@"later is %@", later);  


        //將時間戳轉換成字符串  
        NSString *str = @"123456789";  
        NSTimeInterval second2 = [str doubleValue];  
        NSDate *date3 = [NSDate dateWithTimeIntervalSince1970:second2];  
        NSLog(@"date3 is %@", date3);  

        //格式化日期類  
        NSDateFormatter *df = [[NSDateFormatter alloc] init];  
        [df setDateFormat:@"yyyy年MM月dd日 HH小時mm分鐘ss秒 ZZZZ"];  

        //將日期按照格式化日期類轉換為字符串  
        NSString *str2 = [df stringFromDate:date3];  
        NSLog(@"str2 is %@", str2);  

        //通過字符串轉換為date  
        NSDate *date4 = [df dateFromString:str2];  
        NSLog(@"date4 is %@", date4);  

    }  
    return 0;  
}  </pre>