Arambh is a Punjabi word which mean "begin" of "start". This term is used to refer to the occasion when the event is started of commenced. "Arambh" of Akhand Paath means the occasion of the "beginning of the Paath". The conclusion of a event is referred to an the "Samapti". Samapti is the opposite of Arambh.
The Samapti of an Akhand Paath is the conclusion or ending of the Paath.