1973 (production)

January

 * 2-3 January - Location filming for Planet of the Daleks took place. (REF: Doctor Who The Handbook: The Third Doctor)
 * 4-5 and 8-9 January - Pre-filming for Planet of the Daleks took place at Stage 3B of Ealing Studios. (REF: Doctor Who The Handbook: The Third Doctor)

February

 * 14 March - April Walker is formally contracted for the role of Sarah Jane Smith. This casting would later be dismissed (but still paid for) due to the protesting of Jon Pertwee.