The most common and most likely answer to this crossword clue is the 4 plus 3 plus 3 letter word NAME THE DAY
I've seen this crossword clue in The Guardian
N
A
M
E
T
H
E
D
A
Y
More clues leading to the result NAME THE DAY
Buddy explains!

The straight part
We know that "Set a Match Date" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case set a match date = name the day.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.