NSDate *today = [NSDate date]; // it will give you current date
NSDate *newDate = [dateFormatter dateWithString:@"xxxxxx"]; // your date 

NSComparisonResult result; 
//has three possible values: NSOrderedSame,NSOrderedDescending, NSOrderedAscending

result = [today compare:newDate]; // comparing two dates

if(result==NSOrderedAscending)
    NSLog(@"today is less");
else if(result==NSOrderedDescending)
    NSLog(@"newDate is less");
else
    NSLog(@"Both dates are same");

从这个答案中得到你的解决方案如何比较Objective-C中的两个日期

got your solution from this answer How to compare two dates in Objective-C