This question already has an answer here:
I filled out a form early November to get a Swiss visa (applying in Singapore but not Singaporean) with my travel dates as 19.12.2017 to 02.01.2018. The first available appointment was on the 1st of December and I took it. During the time in between, my travel dates changed to one week later (both arrival and departure). Now, my travel itinerary and supporting documents all have different dates from the dates on the form. What do I do?
I can fill out a new form with the right dates without paying any fees but the online ID on that form will be different.
As mentioned in the comments, I haven't got my visa yet - the interview is tomorrow.