Try using this array formula
=IF(ISERROR(SMALL(IF($B$1:$B$20="SATURDAY",ROW($B$1:$B$20)),COLUMN(A$1))),"",
INDEX($A$1:$A$20,SMALL(IF($B$1:$B$20="SATURDAY",ROW($B$1:$B$20)),COLUMN(A$1))))
copy across as many as might be needed.
This is an array formula.
This means that you use...