You said: Go to your outlook calendar via the internet (on your PC). Click on the settings cog and click on "options." Under "Select when to delete your completed tasks," select "Never."
I cannot find a line that says "Select when to delete your completed tasks" under Options. Your suggestion may apply to outlook in general. The problem of disappearing completed tasks old entries occurs on my window phone. I still see the items on the web Microsoft account. I would like to keep my mail on my device and not have it disappear from my hands. I find that extremely irritating.
Any other ideas, anyone?
Not sure it actually works, just changed the setting for my account, so we'll see if it syncs old appointments, just keeps new ones, or continues to remove them from my phone... but I guess the theory is that making them stay on Outlook.com makes them stay on your phone when it syncs...
To get to the option, go to Outlook.com and log in...
Click the icon on top left that has a grid of 3x3 squares...
Select Calendar...
Hit the Settings button (Gear) near top right...
Hit "Options"...
Scroll down towards bottom to find "Select when to delete your completed tasks"...