As you use and resave them, your 2022/23 data based save games, editor and workshop files and new games, will correct dates to 2022/23 where necessary. (e.g. start on 1st August 2022 where it previously started on 1st August 2021)
It is recommended that you backup any game files in your "Documents\Alternative Software\RUTM4" before playing.
Your save games for the autosave and slots 1 - 6 and editor files for slots 1 - 4 are named the following:-
RUTM4_AS.dat
RUTM4_SG1.dat
RUTM4_SG2.dat
RUTM4_SG3.dat
RUTM4_SG4.dat
RUTM4_SG5.dat
RUTM4_SG6.dat
RUTM4_Editor1.dat
RUTM4_Editor2.dat
RUTM4_Editor3.dat
RUTM4_Editor4.dat
The workshop folder is "Workshop".
The settings file is "RUTM4_Settings.dat".