At least for three months, except:

(i) for those households which at the time of initial certification had their certification process completed after the 15th day of the month of application and also had circumstances which warranted it, the certification period shall be increased by one month;

(ii) when the household cannot reasonably predict what its circumstances will be in the near future, or when there is a substantial likelihood of frequent and significant changes in income or household status, the certification period shall not be more than two months;

(iii) for those households which have little likelihood of changes in income and household status, the certification period shall be up to 12 months;

(iv) for those households in which all adult household members are disabled or elderly persons with very stable income, the certification period shall be up to 24 months;

(v) for those households whose primary source of income is from self-employment (including self-employed farmers) or from regular farm employment, including farm workers whose annual salaries are paid on a scheduled and unchanging monthly basis, provided income can be readily predicted and household circumstances are not likely to change, the certification period will be up to 12 months;

(vi) for all cases subject to six-month reporting under subdivision (d) of this section, the certification period will, notwithstanding any other provision of this subdivision, be six months, except for those households residing within social services districts that have been given written permission by the Office of Temporary and Disability Assistance to lengthen the certification periods to more than six months but not longer than 12 months. For those social services districts authorized to lengthen the certification periods beyond six months, households subject to six-month reporting shall be required to submit a periodic report in the sixth month in accordance with subdivision (e) of this section; and