Why is it?

Why is it that people are writing that at 01:02:03 this morning, that is, on 04/05/06, we had a set of numbers (01:02:03 04/05/06) we won’t see again for 1000 years?

How are they planning to note 01:02:03 of April 5, 2106? Isn’t that just 100 years? Won’t that be 01:02:03 04/05/06 too?