We're starting to go in circles, but here's your quote with the preceding sentence, emphasis mine. You're discussing an online test, not really a take home as described in the article.
> Take-home coding tests used to be rare, deployed only if an employer needed to be further convinced. Now interviewees are regularly given projects described as requiring just two to three hours that instead take days of work.
[Edit]
They should probably call it a "take home project" to be more accurate. It can include front and back end code, tests, documentation, design, styling, etc. etc. "2-3 hours," yea right.
What's the difference between a "take home coding test" and an "online test"? As far as I can tell, these are functionally identical perhaps save for the submission mechanism.
Explain to the candidate that there will be a 3 hour time limit enforced once the prompt is revealed. Close submission 3 hours after the candidate chooses to reveal the prompt. This could easily be done in GitHub, if the submission mechanism is pushing updates to the company's repo. Voila, you have enforced a 3 hour time limit on your "take home coding test".
> Take-home coding tests used to be rare, deployed only if an employer needed to be further convinced. Now interviewees are regularly given projects described as requiring just two to three hours that instead take days of work.
[Edit]
They should probably call it a "take home project" to be more accurate. It can include front and back end code, tests, documentation, design, styling, etc. etc. "2-3 hours," yea right.