iPhone开发--计算两个日期的时间间隔 年 月 日

NSDateComponents *comps = [[NSDateComponents alloc] init];
[comps setDay:6];
[comps setMonth:5];
[comps setYear:2004];
NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
NSDate *endDate = [[NSDate alloc] init];
NSDate *startDate = [gregorian dateFromComponents:comps];
[comps release];
unsigned int unitFlags = NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit;
NSDateComponents *comps2 = [gregorian components:unitFlags fromDate:startDate  toDate:endDate  options:0];
int days = [comps2 day];
int months = [comps2 month];
int years = [comps2 year];

参考自:http://hi.baidu.com/hh20040410/item/6725435038b5a6978d12ed62