Mo. Rev. Stat. § 506.090: Clerk's office open, when.

The clerk's office with the clerk or a deputy in attendance shall be open during business hours on all days except Sundays and legal holidays. All motions and applications in the clerk's office for issuing mesne process, for issuing final process to enforce and execute judgments, and for other proceedings which do not require allowance or order of the court are grantable as of course by the clerk; but this action may be suspended or altered or rescinded by the court upon cause shown.