转载自：http://zxs19861202.iteye.com/blog/1527081
1 // 当前时间创建NSDate
NSDate *myDate = [NSDate date];
NSLog(@"myDate = %@",myDate);
2 //从现在开始的24小时
NSTimeInterval secondsPerDay = 24*60*60;
NSDate *tomorrow = [NSDate dateWithTimeIntervalSinceNow:secondsPerDay];
NSLog(@"myDate = %@",tomorrow);
3//根据已有日期创建日期
NSTimeInterval secondsPerDay1 = 24*60*60;
NSDate *now = [NSDate date];
NSDate *yesterDay = [now addTimeInterval:-secondsPerDay1];
NSLog(@"yesterDay = %@",yesterDay);
4//比较日期
BOOL sameDate = [now isEqualToDate:yesterDay];
NSLog(@"sameDate = %lu",sameDate);
4.1//获取较早的日期
NSDate *earlierDate = [yesterDay earlierDate:now];
NSLog(@"earlierDate = %@",earlierDate);
4.2//较晚的日期
NSDate *laterDate = [yesterDay laterDate:now];
NSLog(@"laterDate = %@",laterDate);
//两个日期之间相隔多少秒
NSTimeInterval secondsBetweenDates= [yesterDay timeIntervalSinceDate:now];
NSLog(@"secondsBetweenDates= %lf",secondsBetweenDates);
//通过NSCALENDAR类来创建日期
NSDateComponents *comp
= [[NSDateComponentsalloc]init];
[comp setMonth:06];
[comp setDay:01];
[comp setYear:2001];
NSCalendar *myCal = [[NSCalendaralloc]initWithCalendarIdentifier:NSGregorianCalendar];
NSDate *myDate1 = [myCal dateFromComponents:comp];
NSLog(@"myDate1 = %@",myDate1);
//从已有日期获取日期
unsigned units = NSMonthCalendarUnit|NSDayCalendarUnit|NSYearCalendarUnit;
NSDateComponents *comp1 = [myCal components:units fromDate:now];
NSInteger month = [comp1 month];
NSInteger year = [comp1 year];
NSInteger day = [comp1 day];
//NSDateFormatter实现日期的输出
NSDateFormatter *formatter = [[NSDateFormatteralloc]init];
[formatter setDateStyle:NSDateFormatterFullStyle];//直接输出的话是机器码
//或者是手动设置样式[formatter
setDateFormat:@"yyyy-mm-dd"];
NSString *string = [formatter stringFromDate:now];
NSLog(@"string = %@",string);
NSLog(@"formater = %@",formatter);
//获取日期格式对象
- (NSDateFormatter *)dateFormatter {
if (dateFormatter == nil) {
dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateStyle:NSDateFormatterMediumStyle];
[dateFormatter setTimeStyle:NSDateFormatterNoStyle];
}
return dateFormatter;
}