(a) On and after the first day of July, one thousand nine hundred eighty, no employer shall employ any of his employees for a workweek longer than forty hours, unless such employee receives compensation for his employment in excess of the hours above specified at a rate of not less than one and one-half times the regular rate at which he is employed. (b) As used in this section the "regular rate" at which an employee is employed shall be deemed to include all remuneration for employment paid to,