Firstly, I presume you meant Feb 18 - Aug 18: Sabbatical?
Whether you can leave it off depends on what you were doing in that period and the reason for the sabbatical. It would be fine if there was a clear reason why you wanted to take time off and the fact your boss brought you back would be a good signal. Equally, it would be important to demonstrate what you were doing at that time - studying, working, travelling etc.
With both of those, I think you can should highlight it on the CV (for example I highlight a gap year taken), especially if out of university and you were travelling for example. If not then don't worry about leaving it off, in my opinion, but be able to voice it over.