If you're so overworked that you don't think you have time for ten minutes of meditation every day, then your time management is poor and needs a re-evaluation of priorities.
Do you say the same thing about the gym, or sleep time? Are you too busy to rest in bed for 7-8 hours a night?
A ton of people don't go to the gym or sleep enough because they feel they don't have enough time. I'm just so confused by the question. It's well documented that parents are sleep deprived and it's a common "joke" that in college you can only pick 2 out of 3 : good grades, a social life or sleep. There's actually no upper limit to how long you can spend just on your studies.
You can still meditate with focus on breathing for even 1 minute. It may not be as effective as if you had more time, but I used to do that on the bus to work or even at work when taking a break so you can still do something.
If you can, meditate for 10 minutes a day.
If you're too busy, then meditate for 30 minutes a day.