Thou shalt therefore keep this ordinance in its season from year to year.
Thou shalt therefore keep this ordinance in his season from year to year.
You shall therefore keep this ordinance at this time from year to year.
So you should follow this regulation at its appointed time every year.
You will keep this observance, at the established time, from day to day.
Thou shalt keep this observance at the set time from days to days.