Upstream tallyman gets up to date (14)

I believe the answer is:

countercurrent

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'upstream tallyman' is the definition.
Although both the answer and definition are singular nouns, I cannot see how they can define each other.

'gets up to date' is the wordplay.
'gets' becomes 'counter' (I can't justify this - if you can you should believe this answer much more).
'up to date' becomes 'current' (I've seen this in another clue).
'counter'+'current'='COUNTERCURRENT'

Can you help me to learn more?

I've seen this clue in the Sydney Morning Herald.

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