If you are new to computers, then it will take a bit more than a month. And if you have experience in solving issues on the computer, then less than a month with 2-3 hours each day will suffice.
If you are struggling to find a suitable course to crack A+ certification, check out this A Plus Certification course from Intellipaat. This 15hrs instructor-led course with 30hrs of projects and assignments will help you gain enough hands-on experience to help you ace A+ certification.