13 is just another number that sits in between 12 and 14.
friday is just another day that sits between thursday and saturday.
day and night are totally governed by the sun.
the sun is for all practical purposes the god,master and absolute lord of the solar system.
earth is in the solar system.
we live on earth
the sun knows not how to count as it has never been indoctrinated to do so
the sun knows not the days of the week as it has never been indoctrinated to know so.
so 13 is irrelevant to the sun as is friday
superstitions have a tendency to be self fulfilling.
so dont create a bad day for yourselves
ok thats my input for what ever its worth
have a great day all.