I am looking to submit my paper in the very near future to a journal. What is a reasonable period of time to give my supervisor to read my paper? I set a deadline with my supervisor of when I would like to submit (a couple of weeks on from sending through the draft of the paper) and hence when they should read the paper by but get the feeling this is going to be missed. Is it ok for me to submit the paper anyway even if they miss the deadline? I only have a finite period of time to finish the paper once it comes back from reviewers, so the sooner it is submitted the better. There's also the possibility that my supervisor will come back and ask to revise some of the manuscript which will hold things up further, so they sooner I know what needs changing, the sooner I can do this and submit.
Set timeline expectations with your supervisor and send calendar prompts/meetings
As a general rule, in a supervisor-student relationship, it is a good idea to have some conversations around timelines for work progress and expected times for work from both parties --- i.e., you should have a good idea of the expectations of progress you need to make and timelines you need to hit, but you should also have a good idea of how long it will take your supervisor to review pieces of work and provide you with a response. Ideally this conversation would occur at the start of candidature and both you and your supervisor would proceed through the whole candidature with clear expectations of timelines from the other. If you have not already had this conversation, it is probably still a good idea to broach it (tactfully) and set down some expectations. (If you want to avoid sounding like you're complaining, feel free to link back to this answer and tell your supervisor that I suggested that you should seek this information.)
Once you've had a conversation about timelines (on both ends) it is good practice to send review tasks to your supervisor in the following form:
Send your supervisor an email setting out the review task clearly and attaching the relevant work;
In both the email and the subject line, clearly state the deadline date when you would like the supervisor to complete review to allow you to meet your schedule for the work. Make sure this is a reasonable amount of time for review that is in line with previous discussions of review expectations (and give the supervisor an opportunity to tell you if there is any problem with this);
Accompany the request with a calendar invitation to meet with your supervisor on the date you are expecting to receive the completed review of your work (and make sure that the calendar invitation includes reminders that ping to remind your supervisor of the impending deadline a week out, a day out, etc.). If a face-to-face meeting is not needed then a calendar invitation for a remote call would have the same effect.
If you do all this, your supervisor will have ample opportunity to let you know if the proposed deadline is too fast for them and propose an alternative deadline. If they accept your meeting invitation then they will know that they have an impending deadline to complete review of your work, and that failure to do this will inconvenience you. As noted in the other answer here, academic clocks can run a bit slow --- many academics put off work tasks that are free-floating, and they need deadlines and meetings to keep them accountable. You might find that some supervisors have clocks that run so slow that they still do not have reviews ready in time even under these conditions. Nevertheless, if a supervisor has an upcoming meeting in their calendar to meet/call a student to give them review feedback on work, it is more likely they will force themselves to complete that review in time.
Since you have already set a deadline for this piece of work, I recommend you now send a meeting invitation to meet with your supervisor the next day, with the invitation clearly stating that it is for delivery/discussion of review feedback. You could even specify the timeline where they send you their review on the previously stated deadline, you then read it overnight, and you meet with them to discuss it the next day. If your supervisor accepts the meeting then it is likely they will get the required review work done in time. In the event that your supervisor misses the deadline, set a new deadline (in a short time) with a reminder noting that the journal requires the resubmission soon. You can also write to the journal editor and ask for more time for resubmission; such requests are often accommodated.
If you have asked your supervisor for help and advice then I suggest that you wait until you receive it. That may mean you dealing with their schedule rather than them dealing with yours. They probably have other things to do. Too much impatience and too much prodding isn't helping your relationship.
But doing something that might later be interpreted as insulting isn't the best career move ("Oh, you were slow so I went elsewhere..."). You may need their help and support for your career.
You are probably over-estimating any risk of being scooped. You want a good paper, not the fastest possible one.
If you haven't learned it already, note that "academic clocks" aren't very precise and usually run slow. One problem is that some things are hard to estimate or predict in advance. Things come up that interrupt schedules. Intellectual work isn't like building with Legos. Professors also often have some issues that many students don't: family, kids, etc. "A week" could easily become two, or even a month. And, giving advice on a paper isn't a trivial task, assuming that the paper itself isn't trivial.
I got this suggestion from a professor who is really successful and sharing it with you here.
Email/meet and politely tell them that you are waiting to receive their feedback soon. You may give them a deadline of a few weeks (usually 15-20 days). After the deadline has passed, you may follow up if they are still reviewing or if they are okay with you submitting the manuscript without their feedback. And tell them explicitly "You are looking forward to hearing from them". If they fail to respond, you can send a final email saying you are submitting the manuscript and assuming they are okay with the manuscript. you may wait 1-2 days to receive their email, or else submit the manuscript.
You are asking the wrong question. You need to ask yourself how long you are going to give him before you start explaining the situation to the department chair. I'd say about 3 months, maybe a bit longer if the advisor is busy, shorter if the advisor is completely unresponsive
Most chairs will not be receptive to Professors not getting on with things like this, and things will happen very fast once this is done.
No you can not just go ahead and submit a paper anyway.