How to perform all delay operations right away with NSOperation or GCD?

Question

I have some operations with different delay times.

While using GCD it looks like:

dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(delayTime * NSEC_PER_MSEC)), dispatch_get_main_queue(), ^{
                        
   // do stuff
                        
});

Butt at some time I wanna perform all operations right away.

Is it possible with NSOperation or GCD?

Thanks