canonical hours

Bishop Cosin wished to define the hours at which it was to be said within certain limits, by adding to “a convenient time before he begin,” “which may be any hour between six and ten of the clock in the morning, or between two and six of the clock in the evening” and although his alteration was not adopted, it serves to show us what were then considered the canonical limits of the times for Mattins and Evensong.

Annotated Prayer Book, 20