Which period shall be considered for interest under section 234B if self-assessment tax is not paid?

Interest under section 234B accrues from the assessment year start until income determination or regular assessment, limited if return accepted.

Interest under section 234B for unpaid self-assessment tax is chargeable from April 1 of the assessment year to the date of determination of income under Section 143(1), and where a regular assessment is made, to the date of such regular assessment; if the return is accepted as filed with no additions, interest is charged only up to the date of filing of the return.