BENEFITS--PORTION OF A WEEK. Notwithstanding any other provisions of this act,¹ the Commission may by rule prescribe that the existence of unemployment, eligibility for benefits and the amount of benefits payable shall be determined, in the case of any otherwise eligible claimant who, within a week of unemployment, is separated from, or secures, work on a regular attachment basis, for that portion of the week occurring before or after such separation from or securing of work, provided such rules are reasonably calculated to secure general results substantially similar to those provided by this act with respect to weeks of unemployment.