Are the fields on the form bound or unbound?
Are the fields on the same form as the button or a different form?

On the same form:
OrderDate = Date()
ShippedDate = Date()

On a different form (the form has to be open):
Assuming ShipAddress is the name of your form
Forms!ShipAddress!OrderDate = Date()
Forms!ShipAddress!ShippedDate = Date()

If the fields are unbound or the form is closed you can use an SQL statement.

Thanks.
The fields are not on the same form or on a different form, the only place is in the table.
The Command Button does some queries append and at the end it has to fill in the table the 2 fields, it can not be done through a form or an append query

In VBA, you can use the Recordset object to add or edit records in a table.  Are you adding a new record with dates, or editing an existing record to put dates in?  If it's editing an existing record, you also need to specify a criteria to choose which record(s) to edit.  This is a major topic in Access and you may need to take some courses from this site.

Thanks