Add the day of signing

Error²Federal courts, Illinois courts21st and 22nd editions

A treaty citation whose date slot, immediately before the source, names the month and the year but drops the day of signing.¹

1. 1R. 21.4.4 Date of Signing. Tables: T4 Treaty Sources.
2. 2An error: the rule in note 1 allows one form, and this is not it.