I have created several integer type fields to calculate the difference between the target date and actual completion date of other fields. For example, Design Agreement Over/Under is calculated on the difference between Design Agreement Target Date and Design Agreement Completion Date fields. The Over/Under field is using the formula subtract(daysUntil($dsgn_agrmnt_target_date_c),daysUntil($dsgn_agrmnt_completion_date_c)) to create the calculated value.
This in itself is not an issue, however, when there is no date entered in the Completion Date field, the Over/Under field is showing a random negative number (I'm assuming based on today's date) and this in return in returning false data on a report I have created to show the average of the over/under fields.
Is there any solution that will only return a value in the Over/Under field if both the Target Date and Completion Date fields contain dates and remains blank if one of the fields is empty?