ios-日期组件

日期组件在项目开发中用的不多 偶尔也会用到
系统给我们提供了一些功能较为完善的类
我们可以直接使用

- (void)showDate
{
/**
*  日历类
*
*  @return
*/
NSCalendar *calendar = [NSCalendar currentCalendar];

/**
*  获取系统当前时间
*
*  @return
*/
NSDate *date = [NSDate date];

/**
*  日期组件
*
*  保存 年月日时分秒周
*/

/**
*
NSCalendarUnitEra                = kCFCalendarUnitEra,
NSCalendarUnitYear               = kCFCalendarUnitYear,
NSCalendarUnitMonth              = kCFCalendarUnitMonth,
NSCalendarUnitDay                = kCFCalendarUnitDay,
NSCalendarUnitHour               = kCFCalendarUnitHour,
NSCalendarUnitMinute             = kCFCalendarUnitMinute,
NSCalendarUnitSecond             = kCFCalendarUnitSecond,
NSCalendarUnitWeekday            = kCFCalendarUnitWeekday,
NSCalendarUnitWeekdayOrdinal     = kCFCalendarUnitWeekdayOrdinal,
*
*  @param NSCalendarUnit
*
*  @return <#return value description#>
*/
//    NSDateComponents *componets = [calendar components:NSCalendarUnitYear | NSCalendarUnitMonth | NSCalendarUnitDay | NSCalendarUnitHour | NSCalendarUnitMinute | NSCalendarUnitSecond | NSCalendarUnitWeekday fromDate:date];

NSDateComponents *componets = [calendar components:NSCalendarUnitYear | NSCalendarUnitMonth | NSCalendarUnitDay | NSCalendarUnitHour | NSCalendarUnitMinute | NSCalendarUnitSecond | NSCalendarUnitWeekday fromDate:date];

/*
周日：1
周一：2
*/
NSLog(@"%ld/%ld/%ld  周%ld",componets.year,componets.month,componets.day,componets.weekday - 1);

NSDate *date1 = [NSDate date];
NSDate *date2 = [NSDate dateWithTimeInterval:3600 sinceDate:date];

/**
*  1.两个时间相差多少秒 ABS
*
*  @return
*/
[date1 timeIntervalSinceDate:date2];

/**
*  2.date 距离1970年1月1号的秒数
*
*  @return
*/
NSTimeInterval seconds = [date1 timeIntervalSince1970];

[date1 timeIntervalSinceReferenceDate];

/**
*  指定距离现在时间差多少秒
*
*  @return
*/
[date1 timeIntervalSinceNow];

}