The Washing of the feet is a Catholic ceremony which is held on Holy Thursday (also known as Maundy Thursday). It involves the priest inviting (or selecting beforehand) for people to come out to the altar, sit on designated seats and have their feet washed with oils and water. In a local parish they will usually invite a member from the following groups:-
A child from the children's liturgy group with their parent. Any disabled/handicapped members of the parish. Any foreign people to the parish, any people of another race or another language. Local parents and children. Eucharistic Ministers.
The choir will sing during the ceremony takes place and this ceremony is used to remember when Jesus asked Peter can Jesus was his feet. Peter said no and Jesus exclaimed, "You should all wash eachothers feet. If you take God, you shall allow me to wash your feet".
Owing to the general use of sandals in Eastern countries the washing of the feet was almost everywhere recognized from the earliest times as a duty of courtesy to be shown to guests (Genesis 18:4, 19:2; Luke 7:44, etc.).
canon xlviii directs that the feet of those about to be baptized are not to be washed by priests but presumably by clerics or at least lay persons.
Hence the washing of the feet was in many places assigned to another day than that on which the baptism took place.