Canon LI.
Canons of Local Councils Received Ecumenically (Ancyra, Gangra, Neocaesarea, Antioch, Laodicea) · The Seven Holy Ecumenical Councils
The nativities of Martyrs are not to be celebrated in Lent, but commemorations of the holy Martyrs are to be made on the Sabbaths and Lord’s days.
LocalE 5.58.2
By this canon all Saints-days are forbidden to be observed in Lent on the days on which they fall, but must be transferred to a Sabbath or else to the Sunday, when they can be kept with the festival service of the full liturgy and not with the penitential incompleteness of the Mass of the Presanctified. Compare canon xlix. of this Synod, and canon lij. of the Quinisext Council.
LocalE 5.58.6
The whole of Lent is a time of grief for our sins, and the memories of the Saints are not kept except on the Sabbaths.
LocalE 5.58.8