The first thing to do to determine the meaning of the term per diem is to discover its etymological origin. In this sense, it should be noted that it is a word that derives from Latin, from “viaticum”, which in turn comes from “via”.
The "viaticum" was used to refer to the provision of food and money that a person needed to travel. However, during the Middle Ages, it was used to mention a tax that was charged to the whole person who wanted to travel a path that belonged to the lands of some feudal lord.
The concept, therefore, is used to name the money waves species that are given to a person for sustenance during a trip .
For example: “The per diem that the company gave me is barely enough to eat”, "I still haven't paid the per diem last month ... could you find out what happens?", "As I spent little on food, I had money left over from the per diem".
The per diem can be delivered to the traveler before your departure , in order to have the means to survive during the trip. Suppose an employee of a company multinational is sent from Chile toward Germany to attend a conference. The head of this person gives you money as a per diem before you leave, so you can pay for the hotel, eat and travel on German soil.
In other cases, per diem is paid after spending . A young man who collects a technology company makes several trips per day, spending money on tickets train , underground and bus (collective). Each day, when the end of working hours comes, presents the travel vouchers in the administration of the company and receives the corresponding money. This means that if the worker spent 45 pesos on per diem, then he recovers them.
In the field of religion , is called per diem sacrament which is granted to a patient who is about to die. This sacrament consists in giving communion to the dying as a preparation for his departure.
That religious "rite" we can underline that it comes from an old Greco-Roman ritual in which a coin was introduced in the mouth of the deceased, under the tongue, as a way to pay the tax of passage to Hades. That currency was known as "obolus", the Greek term, and also as "viaticum", the concept in Latin.
The per diem in this sense, giving the dying communion, is established that it does not have to occur in some specific circumstances. It is exactly determined that it should not be done when the person in question cannot swallow, when he is unconscious or directly when he rejects with absolute decision to receive that sacrament.
Naturally, this process is carried out by the pastor, who must do it when it is clear that the dying person is still in full use of what his mental faculties are.