you would need to create a recordset to compare the entered date with the date in table 1
SELECT table1.DateColumn from table1 where DateColumn >= paramEnteredDate
create a parameter:
Default Value: -1
Runtime Value: $_POST['dateFormElement']
you may need to use date formatting on the DateColumn to get the entered format to match the format in the database:
Then in the Insert Record behavior for table 2, you can use the Recordset Not Empty trigger.