For weeks beginning on or after July 1, 1991, each eligible individual who is totally unemployed or part totally unemployed in any week shall be paid with respect to such week a benefit in an amount equal to his weekly benefit amount less that part of his wages, if any, payable to him with respect to such week which is in excess of Forty Dollars ($40.00). Such individuals must have been totally unemployed or part totally unemployed for a waiting period of one (1) week during which he earned less than his weekly benefit amount plus Forty Dollars ($40.00). Such benefit for a benefit year effective on or after October 1, 1983, if not a multiple of One Dollar ($1.00), shall be computed to the next lower multiple of One Dollar ($1.00). Provided, however, that remuneration for "inactive duty training" or "unit training assembly" payable to such eligible individual who is a member of any of the reserve components, or remuneration for jury duty pursuant to a lawfully issued summons therefor payable to such eligible individual, shall not be considered wages which serve to reduce the otherwise payable benefit amount. In determining whether an eligible individual is unemployed during a week, the date of commencing a shift shall determine the week for which the earnings are deducted.