I have a formula field that shows either the user selected "start date" or the maximum date already in the Dates subform, which ever is greater. However, whenever the form is opened for edit, the field is blank. Adding a date, or changing the start date causes the field to start working again. Can anyone see what is wrong with my formula that's causing this? Note, I needed to add the Number_Of_Dates field as input.Dates.length() didn't work in the formula field.