Dictionaries(dictionary.com, OALD etc.) suggest that leave (absence from work) is a noun- uncountable, which means it has to be "leave" for plural. Also, searching SE to find Applying/earning/validating leave and What does the "leave" mean in "parental leave" and "unpaid leave"? did not help. The title I used might not be explanatory per se, I couldn't think of a way to better phrase it.
I forwarded a combined leave request to my boss at work for several occasions at once. For instance, I requested for a casual leave on Friday, 6th July and Friday, 13th July and additionally a long planned leave from Wednesday, 25th July till Friday, 24th August.
In reply, the approval e-mail read
Approved, forwarded leaves are granted.
N.B: Please remain reachable on your cell phone and e-mail during all your
leaves.
In my understanding, it should still be leave, but somehow leaves started sounding more correct as the reference was made to several instances of my leave (M-W illustrates an example and uses it for plural and wiktionary too). Is there a word "leaves" for multiple instances of leave if combined? Please quote a reference and any other usage.
Edit: added references which caused more confusion.
Best Answer
Leave may be used as a countable or uncountable noun when referring to the period of time one is away from a job.