Thank you very much for your answer and for your help.
[The number of days on their current Type C visa is 90 days, so they will not exceed the number of days granted by the visa at that date]
They already booked a EuroStar ticket from London to Paris on 31-03-2007
do you mean they might have a problem at the French port of entry
because their Type C visa is valid until midnight that day?
Someone told me that with a type D visa, a student is allowed one stop at a Schengen country for a maximum of 5 days before going to his main destination for study. Any idea if this information is true?
If yes, can they wait at the train station in France until after midnight, so they pass the police port of entry on 01-04-2007 using their Spanish Type D visa and enter France as some kind of "transit" for 5 days.
Thanks again for your help.