The Collaborative International Dictionary of English v.0.48:

Probatory \Pro"ba*to*ry\, a. [Cf. F. probatoire.]
   1. Serving for trial; probationary. --Abp. Bramhall.
      [1913 Webster]

   2. Pertaining to, or serving for, proof. --Jer. Taylor.
      [1913 Webster]

   Probatory term (Law), a time for taking testimony.
      [1913 Webster]

Bouvier's Law Dictionary, Revised 6th Ed (1856):

PROBATORY TERM. In the British courts of admiralty, after the issue is
formed between the parties, a time for taking the testimony is assigned,
this is called a probatory term.
     2. This term is common to both parties, and either party may examine
his witnesses. When good cause is shown the term will be enlarged. 2 Bro.
Civ. and Adm. Law, 418 Dunl. Pr. 217.