The Collaborative International Dictionary of English v.0.48:

Planner \Plan"ner\, n.
   One who plans; a projector.
   [1913 Webster]

WordNet (r) 3.0 (2006):

planner
    n 1: a person who makes plans [syn: planner, contriver,
         deviser]
    2: a notebook for recording appointments and things to be done,
       etc.

The Free On-line Dictionary of Computing (19 January 2023):

PLANNER

   A language for writing theorem provers by Carl Hewitt
    MIT 1967.  Never fully implemented.

   CONNIVER was an outgrowth of PLANNER and microPLANNER a
   subset.  PLASMA is a PLANNER-like system modelled on
   Actors.  See also POPLER, QLISP, Scheme.

   ["PLANNER: A Language for Proving Theorems in Robots", Carl
   Hewitt, Proc IJCAI-69, Wash DC, May 1969].