In Acts 20.7, we read of the church in Troas, leaving their homes and gathering on the first of the week to break bread (partake of the communion or known by another name, the Lord’s supper). Matt 26.26-29. 1 Cor 10.16. 1 Cor 11.23-26.
This example sets the pattern for when the communion is to be observed with that being Sunday. To be scriptural we must follow the example given by the scripture. If one believes the communion is to be observed once a year, scripture must be produced which authorizes such a procedure. If no bible authority for the act, it becomes the commandments of men. Mark 7.13.
By a careful study of the scriptures provided, we see that every member of the church partakes of the unleavened bread and drinks the cup which is the fruit of the vine (blood of the grape) and this is to be done in memory of the suffering of Christ as He endured the agony of the night and finally the cross itself.
If you visit the Mt Airy church of Christ on a Sunday, this is one of the acts of worship you will see being observed.