Generally if you cannot attend the full day it is recommended that you withdraw your enrolment so that it can be offered to another participant. You are not eligible to receive your certificate (or CPD allocation) if you have not completed the course in full, and it will be to the detriment of your learning and application of skills in practice if you do not receive the full learning package.
In most instances it is a requirement of your role, duty of care and profession to complete the course in full so you can be deemed competent in the area of practice. If you cannot attend the full day please postpone to an alternate time and in the meantime investigate online training options available.