Who was the 'last' substitute host on a major show?

[Kniwt]

Wacthing P+ and Tom talking about Allen hopefully being back soon, I started trying to think of the last time a "major" GS had a substitute host that wasn't part of a "stunt." (By "major" I mean one that's generally known and probably network/syndie, not some community-access show in Windswept Acres, Nebraska. And a "stunt" is like host-swap day on GSN.)

These days, if a host is unavailable, production just simply shuts down and repeats are aired if needed, yes?

I'll open the bidding with Jim Peck on TJW, 1984.

Edit to add: Of course J! and Wheel are current/recent; I guess my mind stopped working in 2000.

[TLEberle]

Vanna White for Pat Sajak’s emergency surgery seems to fit the definition. Meredith Vieira had a raft of substitutes who would take a week at a time.

[Blanquepage]

Wouldn't the myriad of Jeopardy guest hosts prior to Mayim & Ken becoming permanent fixtures count?
Going back a little further to TJW, Jim also subbed for Bill when he was under the weather in 1986. Let's also not forget Geoff in for Monty on LMaD.

[thomas_meighan]

Also Jamie Farr for Tom Kennedy on “Wordplay” in 1987.

Edit to add: And Mark Goodson for two days of “To Tell the Truth” in 1991.

[WilliamPorygon]

Merideth Vieira had guest hosts fill in for her somewhat regularly during her run hosting Millionaire.

[Kevin Prather]

Merideth Vieira had guest hosts fill in for her somewhat regularly during her run hosting Millionaire.

This is probably the last case of bringing in a sub host being a standard practice. Everything since then has either been a one-off situation (Vanna/Pat) or following a host's departure (Trebek).