The most common and most likely answer to this crossword clue is the 17 letter word TWENTY-FOUR-SEVEN
I've seen this crossword clue in The Times
T
W
E
N
T
Y
-
F
O
U
R
-
S
E
V
E
N
More clues leading to the result TWENTY-FOUR-SEVEN
Buddy explains!
The straight part
We know that "All the time" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case all the time = twenty-four-seven.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.