iPhone开发--NSDate操作

NSDate//得到当前的日期NSDate *date = [NSDate date];NSLog(@"date:%@",date);//得到(24 * 60 * 60)即24小时之前的日期，dateWithTimeIntervalSinceNow:NSDate *yesterday = [NSDate dateWithTimeIntervalSinceNow: -(24 * 60 * 60)];NSLog(@"yesterday:%@",yesterday);NSDateFormatter *formatter =[[[NSDateFormatter alloc] init] autorelease];NSDate *date = [NSDate date];[formatter setTimeStyle:NSDateFormatterMediumStyle];NSCalendar *calendar = [[[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar] autorelease];NSDateComponents *comps = [[[NSDateComponents alloc] init] autorelease];NSInteger unitFlags = NSYearCalendarUnit |NSMonthCalendarUnit |NSDayCalendarUnit |NSWeekdayCalendarUnit |NSHourCalendarUnit |NSMinuteCalendarUnit |NSSecondCalendarUnit;//int week=0;comps = [calendar components:unitFlags fromDate:date];int week = [comps weekday];int year=[comps year];int month = [comps month];int day = [comps day];//[formatter setDateStyle:NSDateFormatterMediumStyle];//This sets the label with the updated time.int hour = [comps hour];int min = [comps minute];int sec = [comps second];NSLog(@"week%d",week);NSLog(@"year%d",year);NSLog(@"month%d",month);NSLog(@"day%d",day);NSLog(@"hour%d",hour);NSLog(@"min%d",min);NSLog(@"sec%d",sec);//得到毫秒NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];[dateFormatter setDateStyle:NSDateFormatterMediumStyle];[dateFormatter setTimeStyle:NSDateFormatterShortStyle];//[dateFormatter setDateFormat:@"hh:mm:ss"][dateFormatter setDateFormat:@"yyyy-MM-dd HH:mm:ss.SSS"];NSLog(@"Date%@", [dateFormatter stringFromDate:[NSDate date]]);[dateFormatter release];==========================================方法一NSDate* toDate1 = [ [ NSDate alloc] initWithString:@"2520-9-26 17:10:00 +0600" ];NSTimeInterval distance = [ toDate1 timeIntervalSinceNow ];NSTimeInterval iDat = distance / ( 86400 ) ;NSLog( @" From now to %@ diff: %f ", [toDate1 description ], iDat );[ toDate1 release ];方法二NSDate* toDate = [ [ NSDate alloc] initWithString:@"2009-9-29 0:0:00 +0600" ];NSDate* startDate= [ [ NSDate alloc] init ];NSCalendar* chineseClendar = [ [ NSCalendar alloc ] initWithCalendarIdentifier:NSGregorianCalendar ];NSUInteger unitFlags =NSHourCalendarUnit | NSMinuteCalendarUnit |NSSecondCalendarUnit | NSDayCalendarUnit| NSMonthCalendarUnit | NSYearCalendarUnit;NSDateComponents *cps = [ chineseClendar components:unitFlags fromDate:startDate toDate:toDate options:0];NSInteger diffHour = [ cps hour ];NSInteger diffMin = [ cps minute ];NSInteger diffSec = [ cps second ];NSInteger diffDay = [ cps day ];NSInteger diffMon = [ cps month ];NSInteger diffYear = [ cps year ];NSLog( @" From Now to %@, diff: Years: %d Months: %d, Days; %d, Hours: %d, Mins:%d, sec:%d",[toDate description], diffYear, diffMon, diffDay, diffHour, diffMin,diffSec );[ toDate release ];[ startDate release ];[ chineseClendar release ];