Why all the hoopla about a date? (Marriages are up by 30% year on year for today over a similar Saturday last year, for example).
Simple. People are meaning machines. We look for hints about what the future will hold and add meaning, often where there is none.
Putting a lucky number on your marriage certificate is just as silly as all the other cues (from the typeface in the ad to the tie on the applicant's neck) that we use to make decisions.