The season after Pentecost, according to the calendar of the church year (BCP, p. 32). It begins on the Monday following Pentecost, and continues through most of the summer and autumn. It may include as many as twenty-eight Sundays, depending on the date of Easter. This includes Trinity Sunday which is the First Sunday after Pentecost. The BCP provides proper collects and readings for the other Sundays of the season. These propers are numbered and designated for use on the Sundays which are closest to specific days in the monthly calendar, whether before or after. For example, Proper 3 is designated for use, if needed, on the Sunday closest to May 25. Proper 29 is designated for use on the Sunday closest to Nov. 23. Prior to the 1979 BCP, Sundays in this long period of the church year were identified and counted in terms of the number of Sundays after Trinity Sunday instead of the number of Sundays after Pentecost. This period is also understood by some as "ordinary time," a period of the church year not dedicated to a particular season or observance, as in the Roman Rite adapted after Vatican II. See Ordinary Time.
Glossary definitions provided courtesy of Church Publishing Incorporated, New York, NY,(All Rights reserved) from "An Episcopal Dictionary of the Church, A User Friendly Reference for Episcopalians," Don S. Armentrout and Robert Boak Slocum, editors.