Returns the zero-based day of week (0 means Sunday,1,2,3,4,5,6) of the
specified unix time.
int timedayofweek(long timeb // unix time
);
Parameters date [in] long as number of seconds elapsed since midnight (00:00:00), January 1,
1970. Returned value The zero-based day of week (0 means Sunday,1,2,3,4,5,6) of the specified
date. Example:
int weekday=timedayofweek(timeb(0));
// day is 2 - Tuesday