I work in sales and each day I like to record how many sales I have done in the day view 10am slot. However I've noticed after a few months all inputted data disappears. My current phone is the Lumia 930 but I had the same problem with the Samsung Ativ S. SD I don't believe it is a hardware problem. Can this data bd retrieved and is there a way to stop it from being lost in the first place. I would appreciate any help offered.
It is not being erased, what is happening is that your account settings are configured to download the calendar and emails items for the past given numbers of days. They still exist in your account online, but your phone is only showing you a little portion of those.
If you want to change this behavior go to: Settings - email + accounts - Microsoft Account (or the one you are using to store things in your calendar) -> from here select Download email from option with the value you want
Take into account that selecting the option
any time will probably fill your phone with a lot of emails and calendar events. Not something to worry about if you have plenty space in your device though.