In practical monetary transactions, the supplier typically offers a maximum tolerable settlement delay to its retailer to stimulate sales volume. This paper examines a time-dependent nonlinear ramp curve demand and trade credit model for products having maximum life duration while accounting for these fluctuations and assuming time-varying holding costs. Besides that, many products constantly degrade and should not be sold after their expiration dates. The non-linear ramp curve demand rate is deterministic, varies with time up to a certain point in time (the breakthrough point), and then becomes constant. The breakthrough point is assumed to have occurred within the cycle length. Three situations are considered: (i) the payment settlement delay period is less than the breakthrough point of demand; (ii) the payment settlement is greater than the breakthrough point of demand; and (iii) the payment settlement is greater than the cycle length. The best optimality is compared through the numerical examples. The problem of generating inventory is presented as a nonlinear constraint optimization problem. The numerical examples are also discussed in order to make the results clearer, and the applicability span of the inventory parameters is then demonstrated using the sensitivity analysis.