To keep track of the time/date when records were last modified and who made the modification, you have two options:
1. Set the default value under 'Edit as' settings
To store the login name of the user who made the change, set the default value to:
$_SESSION["UserID"]
To store the modification date and time, set the default value to:
now()
Note: Make sure to clear the AutoUpdate Value field.
2. Modify BeforeAdd/BeforeEdit events
Add the following code to BeforeAdd/BeforeEdit events:
$values["DateUpdated"]=now();
$values["UpdateBy"]=$_SESSION["UserID"];
See also: