The most common and most likely answer to this crossword clue is the 5 plus 3 plus 5 letter word ROUND THE CLOCK
I've seen this crossword clue in The Daily Telegraph
R
O
U
N
D
T
H
E
C
L
O
C
K
More clues leading to the result ROUND THE CLOCK
- Where hands go continuously
- Where the hands go continuously
- How some golf is played, all day and all night
- Where twelve numbers may appear, always
- Golf article on notice for twenty-four hours
- Where working hands must be on the move constantly
- Twenty four seven
- Game dart players may play constantly?
- Game dart players may play all day long
Buddy explains!

The straight part
We know that "Game dart players may play/all day long" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case game dart players may play/all day long = round the clock.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 ROUND THE CLOCK mean?
ROUND THE CLOCK adjective- Continuous; incessant; without interruption; all day long; nonstop: from the concept that it happens while the hands of the clock go all the way around.