It's important that we develop effective strategies for managing your time to balance the conflicting demands of time for study, leisure and earning money
The main thing in time management is i think 'focus '. At the time of working give your hundred percent so that you will not have to think later on that you will have to do this tomorrow or in future days in your work timings. More specifically try to do work in advance or future task if you finish your present task earlier. By this you will have more time to learn something even during work timings.
In today's era of globalization focus shifting is also an issue which is a person can learn with the passage of time.
Now as far as ' gain ' is concerned it depends on you how do you divide the skill you want to gain in terms of short time intervals. This is the best practice to gain something during your work or even after busy schedule of your work.
you can assign only (one or two) hour(s) as a maximum per day after fajr pray for reading pdf .. then you can specialize first day for your specialization books, next day for human development books and so on
but the most important thing : DON"T PUT YOURSELF UNDER STRESS WHILE GAINING NEW SKILLS