This savegame collection contains all ingame days, plus one right after the intro and one of the finale. As far as I can tell, these should be all checkpoints of the game.

Download Mirror 1[mega.nz]
Download Mirror 2[www.dropbox.com]

Note: 7-Zip, WinRAR or other software that can extract 7z files is required.

On Windows the savegames can be found in this path:
You can access that path by copy and pasting it into the File Explorer address bar, as shown in this screenshot:

On Linux the savegames can be found in this path:
Note: The tilde (~) in the path represent your home directory, in case you want to follow it manually.

If you installed the game on a different drive than your root drive, navigate to the location of your Steam library on that drive and then follow this path: