Imagine a calendar with the months. You must fill out every month.
Note that you may have finished your school on 31-Aug-2014 and started working 01-Sep-2014.
In this case, you should write:
2014-08 Studying
2014-09 Working
You don't need to start the next activity in the same month of the previous one, but you definitely should not jump a month.
Other example, if you have finished your school in 30-Jul-2014, and started working on 01-Sep-2014.
You should write:
2014-07 Studying
2014-08 Looking for a job
2014-09 Working
But if you finished your school in 10-Jul-2014, and started working on 31-Aug-2014, you should write:
2014-07 Studying
2014-08 Working
Since we do not have to write the day of the month, in this case it will be continuous, you have filled the July-2014, and August-2014, even if you were not working almost the entire month of August. It is not necessary, using the last example, to write:
2014-07 Studying
2014-07 Looking for a job
2014-08 Looking for a job
2014-08 Working