If it'll be your first time landing in Canada with zero Canadian experience, it won't matter too much since the time frame you gave is only 3 months long. You'll most likely need to spend up to 6-12 months to find your first job. As you see, starting the job search sooner is always better. So land as soon as you can.
Also remember that some professions are regulated in Canada (like engineering), which means you're going to need a certificate from the corresponding Canadian body. For engineering, it takes at least 4 months (even for citizens) to get any sort of certificate and you're at a disadvantage until you get your certificate. Again, landing late will mean you get your certificate late. Land as soon as possible and start building your life in Canada. Also research what you can do without being in Canada to accelerate some of these processes.