Pentecost designates the feast on the 50th day after Easter (this is also the 10th day after the Ascension of Christ) According to old practice, Easter sunday has been counted as the first day. Thus, Pentecost sunday always falls in the time span between May 10th and June 13th. On Pentecost the sending of he Holy Spirit is remembered as it is described in the New Testament. Thus, the foundation of the church is celebrated. Valentin Rathgeber has also written several compositions for Pentecost, i.e. offertories and hymns.