Crossword Genius

They're square sundials for example (3-6)

Ross

I believe the answer is:

old-timers

I'm a little stuck... Click here to teach me more about this clue!

'sundials for example' is the definition.
I can't judge whether this definition defines the answer.

'they're square' is the wordplay.
'they're' becomes 'oldtimer' (I can't explain this - if you can you should believe this answer much more).
'square' becomes 's' (abbreviation).
'oldtimer'+'s'='OLD-TIMERS'

Can you help me to learn more?

(Another definition for old-timers that I've seen is " People with long experience, like ancient watches".)

I've seen this clue in The Globe and Mail.
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