The most common and most likely answer to this crossword clue is the 4 letter word YULE
I've seen this crossword clue in The Daily Telegraph
Y
U
L
E
Buddy explains!
The straight part
We know that "this festive tide" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case this festive tide = yule.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.
What does YULE mean?
YULE noun- Alternative letter-case form of Yule