#! perl -slw
use strict;

sub getDays{
	qw(
		Sunday
		Monday
		Teusday
		Wednesday
		Thurday
		Friday
		Saturday
	) [ grep{ $_[0] & (1 << $_) } 0..6 ]
}

print "@{[getDays $_]}" for 1 .. 127;

__END__
C:\test>213473
Monday
Teusday
Monday Teusday
Wednesday
Monday Wednesday
Teusday Wednesday
Monday Teusday Wednesday
...118 omitted...
Teusday Wednesday Thurday Friday Saturday Sunday
Monday Teusday Wednesday Thurday Friday Saturday Sunday

C:\test>