Question: "What is a convocation?"
Answer: A convocation is a summoned assembly. The convocations commanded in the Mosaic Law were held on special religious days that required a gathering of God’s people. Some translations call the convocations in the Law “sacred assemblies.”
Some examples of convocations in the Bible are Sabbaths (Leviticus 23:2–3); Pentecost (Leviticus 23:21); Passover (Exodus 12:16; Leviticus 23:7); and the Feasts of Weeks, Tabernacles, and Trumpets (Numbers 28:26; 29:1; Leviticus 23:35–36; 23:24). The Feast of Unleavened Bread called for two holy convocations, one on the first day and the other on the seventh day (Exodus 34:18). Every year on the tenth day of the seventh month was the Day of Atonement; Israel was commanded to fast on this day and to gather at the tabernacle or temple. This was called the “holy convocation” (Leviticus 23:27; Numbers 29:7, ESV).
Today, the word convocation used in religious contexts is often associated with the gathering of a synod, a council that meets for the purpose of deciding upon doctrines or the application of doctrines within an organization. A convocation can be an ecclesiastical meeting of importance, an academic meeting led by a university, a gathering of alumni at a college, a meeting of governing officials to fill a chancellorship or other high office, or simply a graduation ceremony.