Anthony J Leonardi, PhD, MS. (2021, December 31). Choose your adventure, friends https://t.co/IpUMR8AoMp [Tweet]. @fitterhappierAJ. https://twitter.com/fitterhappierAJ/status/1476971165042290691

A "false negative" can be made more likely if testing too soon or too late. Though also if there's no virus in the specimen but it is in the human it's arguable if you can even call it a false negative.

But false positives and the timing of a test makes no sense. False positives are inherently independent of when someone is infected... because they're not infected but the test comes back positive. So it's meaningless to say false positives depend on the time of a test.