| Date | Day | Commons day type | Commons praying | Lords day type | Lords praying |
|---|---|---|---|---|---|
| Sunday | 23rd | Prorogation | False | Prorogation | False |
23rd September 1866 is in the prorogation between the 1st and 2nd sessions of the 19th Parliament, being the 1st prorogation of that Parliament.
Papers laid during this prorogation are reported by both Houses in the 2nd session of the 19th Parliament.