The language is decided by a reduction to 2-satisfiability, which is in polynomial time, that carries out the decision itself and writes a formula with no clause for a yes-instance and an unsatisfiable formula for every other word. At zero days every schedule is vacuously fair, so a word RAM program decides it directly from the day count, the parameter and the client count, with no dynamic program needed. At a positive number $m$ of days, a word RAM program reads the instance, checks that every job takes some time and is not due before it starts, checks that the due dates are day-independent, orders the clients by due date, and runs a dynamic program over them that carries for each of the $m$ days the time at which its machine is next free, deciding whether the parameter is met. The number of days is a constant of the reduction rather than part of its input, so the algorithm and its running time depend on $m$, with the exponent of the polynomial growing with $m$.