USE plato;

SELECT
    ni + Interval("P1D"),
    wi + Interval("P1D"),
    ni + Interval64("P1D"),
    wi + Interval64("P1D")
FROM Dates;

SELECT
    Interval("P1D") + ni,
    Interval("P1D") + wi,
    Interval64("P1D") + ni,
    Interval64("P1D") + wi
FROM Dates;

