Assuming this is about a competitive match, "When is the day of my fight?" or more colloquially "When is my fight day"?
I am not sure for athletes, but for normal people this means fighting beside normal sports, eg street fighting or perhaps mix martial arts
Thanks, the sentence just had me wondering whether the meaning waa limited to the sort of event that would be scheduled.
"Day of fight" is not a thing in English. One can talk about the day of an event, whether that event is a concert, sporting match, or as here, fight. I suppose if you were in some activity in which you were, for instance, fighting on some days and coaching on others, you might ask "When is my fighting day," but that would be a very rare usage.