Make field 2 into an unstored calculation returning a number:
= Get( CurrentDate ) - DateSigned
It is important that the calculation is unstored, this forces FMP to update it each time it is needed.
(Being unstored and needing to be re-calculated each time is also a processing overhead which can lead to performance issues when the number of ustored calculations gets large and the record count gets large.)
Thank you Vaughan, a lot simpler than I had anticipated.
Fortunately, in this case the processing overhead is not an issue as the database will stay pretty much fixed to 50 records.
I suppose you could run a script based on a script trigger of onrecordopen
There is no such event as onRecordOpen.
There is an event, onRecordLoad - which is proabably what you mean. But that isn't the same thing.
OnRecordLoad happens when the record becomes the current record.
In FileMaker, opening a record happens when you begin editing it. An open record can't be edited by other users. You must then commit or revert the record to save or discard changes.