My friend is traveling in Europe (Italy, France) and she has two Schengen visas - the current one from Greece that expires on June 23, and the new one, also Greek, that starts on June 24 (thus she doesn't have a gap).
I can't find any info on whether she has to leave Schengen on 23rd and then re-enter on 24th thru Greece, or if she can just stay in Italy (she is way below 90/180 days).
I would like to get a link to any official web site that states that it's fine to stay in Schengen zone between two consequent visas.