Sts Sergius and Herman died about the year 1353. They are also commemorated on September 11 (The translation of their holy relics).
Troparion — Tone 4
Fulfilling the Gospel of Christ and loving him alone, / Despising earthly cares you settled on an island. / There you fought against the invisible foe, / Subjecting your bodies to the Spirit by fasting, vigil and prayer. / Crowned with glory and now standing before the Trinity, / Pray, O Fathers Sergius and Herman, / That our souls may be saved!
Kontakion — Tone 4
You left the world to follow in Christ’s footsteps, / Reaching Lake Neva and the island of Valaam. / There you lived the angelic life / And were translated to the heavenly bridal chamber. / As you stand with the angels remember the children whom you gathered, / That we may joyfully cry to you: / Rejoice, blessed Fathers Sergius and Herman!”