This formula from Jimmy worked -
concat(substring(field1, 6, 2), "/", substring(field1, 9, 2), "/", substring(field1, 1, 4), " ", substring("0", 1, substring(field2, 1, 2) mod 12 + 12 * (substring(field2, 1, 2) mod 12 = 0) < 10), substring(field2, 1, 2) mod 12 + 12 * (substring(field2, 1, 2) mod 12 = 0), substring(field2, 3, 6), " ", substring("AP", 1 + (substring(field2, 1, 2) >= 12), 1), "M")
Where field one is my date field and field two is my time field. Now I just need to remove the seconds from the time.