Maintenance, Clear Data, Automatically Clear Data, Clear financial history over 6 years old is the option you want look for from the main Home Screen.  It should already be set to 6 years, meaning it will keep the current year and 6 prior years.

Make sure you keep a good backup of your file (eg. File, Backup).

I always recommend a File, Save As copy and if your company file is called ABC.sai, I recommend keep your year end file as ABC2019.sai (or whatever year end you are working on).  If your fiscal year is not Dec 31, then I call it ABCT42019.sai.

Then go back to your ABC.sai file and move the session date to the new year.

Thank you so much - been using Sage and Simply for years and  cant believe I didn't  know this !

Worked perfectly