They've probably given that date because it's the next one available but ring the antenatal team and ask them. They'll be able to tell you. Normally electives are at 39+ weeks, because they can have breathing issues before 39 weeks. If you go into labour before that, you just call the labour ward to let them know, and then when you arrive they get you ready for surgery.
Usually if you’re booked for an elective and the baby comes sooner the advice is to quickly and calmly make your way to hospital where they will then do the section right away. That’s what I got told to do if baby started to come before the date I had been given.