USE plato;

SELECT
    a.na - b.ni,
    a.na - b.wi,
    a.naz - b.ni,
    a.naz - b.wi,
    a.nd - b.ni,
    a.nd - b.wi,
    a.ndz - b.ni,
    a.ndz - b.wi,
    a.nt - b.ni,
    a.nt - b.wi,
    a.ntz - b.ni,
    a.ntz - b.wi,

    a.wa - b.ni,
    a.wa - b.wi,
    a.waz - b.ni,
    a.waz - b.wi,
    a.wd - b.ni,
    a.wd - b.wi,
    a.wdz - b.ni,
    a.wdz - b.wi,
    a.wt - b.ni,
    a.wt - b.wi,
    a.wtz - b.ni,
    a.wtz - b.wi

FROM Dates as a CROSS JOIN Dates as b