First of all, I am a beginner at creating formulas. I only have experience with with basic math formulas.
I am trying to create a field that show how long a product was on the market. I have two fields, purchase date and sales date. Purchase is the day we bought the items, Sales date is the date we sold it.
I used the datetime_diff formula but I am getting NaN on items that have not sold yet. How do I create a formula that would show days on market for items that have not sold yet. In other words, the items that have been on market for 30 days would show 31 days tomorrow, 32 days the next day, and so on…
Is a formula like that possible? If not, what are my options to remove the NaN appearing in the field?

