Combining dates for events

There are conspiracy theories about dates and numbers and stuff...

I've seen people combining dates of events... example: John was born 18th July, so John arranges his marriage to July 18th and arrange the marriage of his son to 18th July.

If It was right one time, It'll be right another? Is that it? Like a belief?

[edit on 26-9-2009 by infobrazil]