The most common and most likely answer to this crossword clue is the 6 letter word HOURLY
I've seen this crossword clue in Financial Times
H
O
U
R
L
Y
More clues leading to the result HOURLY
Buddy explains!
The straight part
We know that "as time goes by" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case as time goes by = hourly.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 HOURLY mean?
HOURLY noun- Something produced each hour.
- Occurring every hour.
- Unsalaried, paid by the hour; (by extension) blue-collar.
- At intervals of an hour.