VB.Net - DataGridView update LastUpdated field in SQL Table

Good Day Experts!

I am shopping for assitance with a new task in my project that I do not understand hot to achieve it in VB.net.  I have a DataGridView that presents the User with SQL table data.  The User updates the data ans hits the <Update> button and the updates are written back to the SQL table.

My new task is in that SQL table I need to update the [LAST UPDATED] field when a change is made to a record.  

So far I have gone down this path:
    1)Put [LAST UPDATED] in my DataGridView so it can be in the dataTable that gets pulled
       down from db so I can send changes to it back to the database
    2)So, now have to figure out how to get the current date/time stamp into the
       DataGridView Last Update column when changes to the record in the DataGridView
       is made?
    3)When I run the UpdateCommand then it gets updated back to the database?

Am I on the right track? If, so what do I do next?

Thanks,
jimbo99999