_h_--Trinity Sunday, the octave, or eighth day of the feast of Pentecost, is a church festival held in commemoration of the doctrine of the Trinity. The introduction of this day into the calendar is of comparatively recent date, it being established by Pope Benedict XI, in the year of our Lord 1305. It is probable that the zeal of many Christians against the use of images in the eighth and ninth centuries may have been the first cause of the appointment of a distinct day for meditating upon the nature of the Holy Trinity in unity, or the one true God as distinguished from idols. The reason for its late introduction is that in the creed of the church, and in its psalms, hymns, and doxologies, great prominence was given to this doctrine, and it was thought that there was no need to set apart a particular day for that which was done every day. This is the last of the movable feasts in the ecclesiastical year, being held eight weeks after Easter; so it may happen as early as the 17th of May or as late as the 20th of June. The length of both Epiphany and Trinity-tide depend upon the date of Easter. As Epiphany-tide is shortened by the early date of Easter, so Trinity-tide is lengthened proportionately, and as Epiphany-tide is lengthened by the later date of Easter so Trinity-tide is shortened proportionately; so Trinity-tide may contain no more than 196 days nor less than 161. (See tables at the close of this chapter.) All Saints Day, or All hallowmass (Anglo-Saxon _all_, and _halig_, holy) a festival celebrated by the Roman Catholic and Episcopal churches on the first day of November, in honor of all Saints and martyrs. It was introduced into the Western church in the beginning of the seventh century by Boniface. The number of saints being exceedingly multiplied, it was found too burdensome to dedicate a feast day to each, there being, indeed, scarcely hours enough in the year to distribute among them all. It was therefore resolved to commemorate on one day all who had no particular day. By order of Gregory IV, it was celebrated on the first of November, 834; formerly the first of May was the day appointed. It was introduced into England about 870, and is still observed in the English and Lutheran churches, as well as the Church of Rome on the first of November.