Taking into account empty values in a graph and not in the database

I calculate the duration between two date fields and then make a pie chart. In some cases one of my fields is empty, which gave me a NaN result. I got around this problem by using the formula

IF({Date de création de l'événement},DATETIME_DIFF( {Date de visualisation},
  {Date de création de l'événement},

which allows me to obtain empty values for the values without interest.

When I filter the view for values between 0 and 12, I have 44 records left and on my pie chart I have 34.

This is incomprehensible because by checking these 44 records all include a value between 0 and 12 whereas on my chart I would have to include the empty records to get the 44 values. But in reality I have 44 records with a value and nothing with no value inside theses 44 records… I have the impression that there is a conflict.

Adding a filter to remove the empty fields also has no effect because it conflicts with the filter on the values.

Thank you for your help !

Hey Martin, that’s…pretty weird. Any chance you could send me an invite so that I could help troubleshoot it?

Hey Adam, i was a big mistake from me… Sorry for that