iOS 时间类常用方法

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//当前日前日期

NSDate *today = [NSDate date];

 

//时区

NSTimeZone *zone = [NSTimeZone systemTimeZone];

 

//设置间隔

_interval = [zone secondsFromGMTForDate: today];

 

//今天+8小时（中国上海时区）

today = [today dateByAddingTimeInterval: _interval];

 

//获取明天日期

NSDate *tomorrowDate = [[NSDate alloc]initWithTimeInterval:24 * 60 * 60 sinceDate:[NSDate date]];

 

//日历

NSCalendar *calendar = [NSCalendar currentCalendar];

 

//comps里可以分离出时间年月日等信息

 

NSDateComponents *comps = [calendar components:(NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit | NSWeekCalendarUnit | NSWeekdayCalendarUnit |NSWeekdayOrdinalCalendarUnit | NSHourCalendarUnit) fromDate:tomorrowDate];

 

//获取当前星期几

NSInteger weekday = [comps weekday];

 

//将NSString类型转换成NSDate

 

NSDate *serverDate = [dateFomatter dateFromString:serverTimeStr];

NSDate *createDate = [dateFomatter dateFromString:createTimeStr];

 

//算出两个Date的间隔

NSTimeInterval betweenTime = [serverDate timeIntervalSinceDate:createDate];

//分离出标准格式里的年月日时分秒

 

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

[dateFomatter setDateFormat:@"yyyy-MM-dd HH:mm:ss"];

 

//将string换成formatter形式

NSDate *stringDate = [dateFomatter dateFromString:string];

 

//formatter为月和日

[dateFomatter setDateFormat:@"MM-dd"];

 

//提取字符串中月和日

NSString *str1 = [dateFomatter stringFromDate:stringDate];