Thanks for the reply. However, my university's international office confirmed I would not have to leave Schengen as my visa would be activated automatically on the 25th.

The problem is to activate the visa typ d. You could enter the schengen area on the rights of your american passport and leave it for the UK. UK is not part of schengen. If you come back to the schengen area on August 25 or later you can let stamp your visa. Thanks for the reply. I have a flight ...

Just to clarify: Italy issued my national visa as I'll be studying there, and my travel plans are through various Schengen countries and the UK.

So I'm a US citizen studying in Europe this fall. I'm planning on traveling for 14 days before my semester starts. On my application, I specified that my stay would be 124 days which included the travel period. However, the visa was issued to begin August 25 when I need it to begin August 11 at the ...