ADC accuracy without internal re-calibration

Hello,

I have an application, where I need ADC samples at a fixed rate, if the device is running.

So, I can do a ADC self-calibration at start up and while idle, but not while the application is running.

The application can run for several hours and the temperature can change a lot.

In the datasheet of the STM32f303RB there is a note

“ADC DC accuracy values are measured after internal calibration.�?

Is there a ADC specification, if the ADC self-calibration function is not called regularly?

Or is there any approximation for the temperature and long-term drift?