Which method is used for calculating the interest on drawings if amount withdrawn by partner is unequal and drawn at different dates?

Product method

Product method: When unequal amounts are withdrawn at unequal interval of time , product method is also used for calculating interest on drawings.
Under this method, first we calculate the period of each drawing.
After that each drawing is multiplied with the period to get the product.
Interest on drawings= Total of Products × Rate/100 × 1/12