In some of the Western countries, it has become an annual tradition to celebrate the First Communion during the months of April or May.
Still, this tradition is something relatively new and unique to the Roman Rite of the Catholic Church.
During the first few centuries of Christianity, the three sacraments of initiation which are, Baptism, Confirmation and the Eucharist, were always celebrated together.
This meant that adults, children and babies received all three sacraments when trying to convert them to Christianity.
And this Sacraments, typically take place during the Easter Vigil. At the initial times, it is the duty of the bishop to confer these sacraments, but as Christianity spread in the West, bishops were no longer able to be physically present.
And this resulted in a separation of these sacraments in the Roman Rite, where baptism became a solitary sacrament which is administered by the priest or deacon and later on confirmation would be conferred when the bishop would be able travel to the parish.
Then, the teenagers received first Communion and confirmation comes after it.
As at the 19th century there developed a detailed ceremony in many Western countries where all teenagers received First Communion at the local parish together, and they were dressed in white garments that resembled their baptismal clothing.
This became the practice up until 1910, when Pope Pius X brought down the age of First Communion and encouraged young children to receive the Eucharist at age 7 or 8. Then instead of teenagers to receive First Communion at the parish, it changed to younger children.
The decision to host this ceremony in April or May is extremely based on the celebration of Easter, which in some way brings the connection to the original tradition of receiving the sacraments at the Easter Vigil.
In addition to that, for many centuries the Church gave an instruction to its members to receive holy communion on an annual basis during the Easter season.
And the current Code of Canon Law highlights this “Easter obligation” in (Can.920) after being initiated into the Most Holy Eucharist, each of the faithful have an obligation to receive holy communion at least once a year. And this precept must be fulfilled during the Easter season unless it is fulfilled for a just cause at another time during the year.
Consequently, anyone can receive their First Communion, with the permission of their local priest, and at any time of the year.
However, because of the closeness of the connection of Eucharist to the Easter season, the celebration is mostly done on one of the Sundays following Easter.