When the date of dedication is unknown, the Dedication Festival may be observed on the first Sunday of October (3 October), or on the Last Sunday after Trinity (24 October), or on a suitable date chosen locally.
Dedication Festival

Gold or White

Principal Service
Genesis 28.11-18 or
Revelation 21.9-14
Psalm 122
1 Peter 2.1-10
John 10.22-29

Third Service
Haggai 2.6-9
Hebrews 10.19-25
Morning Psalms
Psalms 48, 150

Second Service
Jeremiah 7.1-11
Luke 19.1-10
Evening Psalm
Psalm 132