Positive periodic solutions in shifts for a nonlinear first-order functional dynamic equation on time scales

Let be a periodic time scale in shifts with period . We consider the existence of positive periodic solutions in shifts for the nonlinear functional dynamic equation of the form x (t) = - a(t) xs (t) +.b(t) f (t, x(h(t))), t. T using the cone theory techniques. We extend and unify periodic differential, difference, h-difference and q-difference equations and more by a new periodicity concept on time scales.