Re-calculate

In Access2000 (frontend) Sql server (backend)

I have a form which had a DueDate field, and a command button which takes the user to a sub-form which allows the user to change the date by a certain number of days, enter a reason why the date is being changed, etc. Once the fields have been filled in, the user exits the subform and returns to the main form called JobTracking. The issue I have, is that the date is not re-calculating unless the user exits the JobTracking main form and then re-enters it. Only then does the field re-calculate the new date.

How do I have the date field re-calculate upon exit of the sub-form and re-entry of the main form?

update the table and refresh your recordset?