Dear Davidson,
My leave was rejected by my boss at the very last minute. I’m so mad! How do I deal with this?
– Miss Overworked

Dear Miss Overworked,
There may be several reasons why your leave was not approved.
Firstly, did you provide sufficient notice period?
Always ensure that you give your manager a heads up so they have sufficient time to plan things ahead before your absence.
Another reason could be that you have insufficient leave balance.
If you are planning to take extra days off without sufficient balance annual leave, chances are your leave request may be rejected.
Other common reasons for rejection are:
(i) You are still a fairly new employee in the organisation.
(ii) The length of your leave – you applied for too many consecutive days.
(iii) The timing – for example, festive period or school holidays, where too many people are on leave at the same time
It is important to remember, however, that your employer can refuse your holiday request, for example, during busy periods.
Although your employer can refuse to give you holiday leave at a certain time, they cannot refuse to let you take your minimum leave entitlement for the year.
Your manager can also cancel your leave after approving it.
Often times it can be frustrating as prior arrangements have been made – and this leaves workers on their own trying to get refunds for airfare and accommodations.
These are some things that you can do prior to making any arrangements or applying for leave:
(i) Know your company leave policies (you can check with HR or read the company handbook).
(ii) Ask at the right time – for example, after you complete a project successfully
One thing to remember is this: At the end of the day, you are working with people.

Sometimes just by being more tactful towards your manager, might get your leave approved.
Hence, not only should the reason for your leave be solid, you need to also justify and convince your manager that everything has been taken care of in your absence and that your work will be done or covered.
Simply by understanding your company policies and people in general will help you deal with situations like this better in future.
Use Colored Brain (check out the video here) to understand how your boss or manager processes information and how you can understand them better. Good luck!
– Davidson