13 We begin the fast of forty days on the first day of the month Phamenoth (Feb. 25); and having prolonged it till the fifth of Pharmuthi (March 31), suspending it upon the Sundays and the Saturdays preceding them, we then begin again on the holy days of Easter, on the sixth of Pharmuthi (Apr, 1), and cease on the eleventh of the same month (Apr. 6), late in the evening of the Saturday, whence dawns on us the holy Sunday, on the twelfth of Pharmuthi (Apr. 7), which extends its beams, with unobscured grace, to all the seven weeks of the holy Pentecost. Resting on that day, let us ever keep Easter joy in Christ Jesus our Lord, through Whom, to the Father, be glory and dominion for ever and ever. Amen. All the brethren who are with me salute you. Salute one another with a holy kiss.
Here ends the sixth Festal Letter of the holy and God-clad Athanasius.
Source: Letters (New Advent)