let rec usun_po_15_30 (list:Wydarzenie list) =
    match list with
    | [] -> []
    | x :: xs ->
        let el = usun_po_15_30 xs
        if x.Godzina.Godzina > 15 then
            if x.Godzina.Minuta > 30 then
                el
            else
                x :: xs
        else
            x :: xs

usun_po_15_30 lista_wyd