“…The theory of impulsive differential equations with variable times is relatively less developed due to the difficulties created by state-dependent impulses. Recently, some interesting extensions to impulsive differential equations with variable times have been done by Bajo and Liz [4], Frigon and O'Regan [5][6][7], Kaul et al [8], Kaul and Liu [9,10], Lakshmikantham et al [11,12], Liu and Ballinger [13], and Vatsala and Vasundara Devi [14,15]. Very recently, by using the Schaefer theorem and the concept of upper and lower solutions, Benchohra et al [16][17][18] have considered different classes of impulsive functional differential equations.…”