The most common and most likely answer to this crossword clue is the 12 letter word TIME-SHARING
I've seen this crossword clue in The Times
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Buddy explains!

The straight part
We know that "holiday option" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case holiday option = time-sharing.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 TIME-SHARING mean?
TIME-SHARING verb- To own or lease (a property) by time-sharing.
- To use (a computer or communications band) by time-sharing.
- The joint ownership or lease of a property by multiple people who can only use it for specified periods every year, or every other year.
- A technique that allows many users to use a central computer simultaneously through remote terminals.