This guide is no longer needed, as the thanksgiving levels have now been added permanently. Now you can just play them normally!

Regardless, I'll leave this up just for reference.

The 4th March 2022 patch removes the thanksgiving levels from the game (probably temporarily, until November). Revert to the 22 November 2021 patch and then change the date to get the levels to reappear.

Credit/Source:
www.reddit.com/r/Steam/comments/611h5e/guide_how_to_download_older_versions_of_a_game_on/

The above thread goes into more detail about downloading older versions of a steam game, but I will summarise below.

1. Open the Steam console:
Either paste the below into a command window (Windows Key + R) or paste it into your internet browser:
steam://nav/console

2. Input the one of the following commands depending on your operating system:

Windows:
download_depot 785790 785791 608276467016171116

Mac:
download_depot 785790 785792 5360367174934013309

Linux:
download_depot 785790 785793 7292507651909993651

3. Wait for Steam to download it. This may take a while, the console will let you know when the download is complete and where the location of the download.

4. Find the downloaded files (likely to be in 'C:\Program Files (x86)\Steam\steamapps\content\app_785790\depot_785791' or similar)

5. Go to your library, find What the Golf, right click and go to Manage > Browse Local files

6. Remove these local files, and replace it with the new downloaded files you found in step 4

You can now launch the previous patch through steam.

From here, the method remains the same as before.

1. Change the date on your PC to 24 November 2021

2. Open the game and the Thanksgiving levels should appear

3. Complete the levels

4. To update your game back to the current version, Go to your Library and right click What the Golf, then go to Properties > Local Files > Verify Integrity of game files