相信很多公司都有此需求，百度+google了半天，最终：

NSDateComponents *currentDate = [NSDate dateComponentsWithDateComponents:[NSDate date]];

NSString* string = [NSString stringWithFormat:@"%ld1231160000",currentDate.year];

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

[inputFormatter setLocale:[[NSLocale alloc] initWithLocaleIdentifier:@"en_US"] ];

[inputFormatter setDateFormat:@"yyyyMMddHHmmss"];

NSDate * inputDate = [inputFormatter dateFromString:string];

NSDate * maxDate = inputDate;

NSDate *minDate = [NSDate dateWithTimeIntervalSince1970:0];

--- 这里是一个分类

+ (NSDateComponents*)dateComponentsWithDateComponents:(NSDate*)endDate{

NSCalendar*calendar = [[NSCalendar alloc]initWithCalendarIdentifier:NSGregorianCalendar];//设置成中国阳历

NSDateComponents*comps = [[NSDateComponents alloc]init];

NSIntegerunitFlags =NSYearCalendarUnit|NSMonthCalendarUnit|NSDayCalendarUnit|NSWeekdayCalendarUnit|NSHourCalendarUnit|NSMinuteCalendarUnit|NSSecondCalendarUnit;

comps = [calendar components:unitFlagsfromDate:endDate];

returncomps;

}