Red Skelton voiced Father Time (whose model is based on Skelton's likeness), and also recreated his popular radio character "Junior" for the voice of the Baby Bear on Fairy Tale Island.
According to Frank Gorshin, who voiced the knight Sir 1023 (Ten-Two-Three), his voice work was all done in one day.
When Father Time shows Rudolph the map of the Time Islands. One of the Islands is 1965. The story begins and ends in that island, a year after the first broadcast of Rudolph the Red-Nosed Reindeer (1964).
The Father Time puppet used in the special still survives to this day due to being sent to Rankin Bass' New York headquarters for publicity purposes after production in Japan wrapped, and has been shown at various conventions over the years with Rankin Bass Historian Rick Goldschmidt.
Paul Frees provided the voices of Santa Claus, Humpty Dumpty, General Ticker, The Great Quarter Past Five, Eon, and 1776 (Sev).