Do you have access to the SQL Server schedule functions?
If you do then you should simply create a new job that runs every Monday at a time prior to your business day start time. The job would call a stored procedure to do the update. This, by far, is the better approach due to the fact that (presumably) the SQLServer would not be shut down, whereas your PC probably is in your absence (or you could be on holiday).
Alternatively, if you can't do that, then you could set up a Windows Scheduled Task that runs on Monday (could be on your specific PC even) that calls an ACCESS app that does the update via the ODBC connection (that you obviously already have).
I've given you a couple of directions to go for starters, but if you need more help just let us know...