Yet another money-grubbing PCN based on timings, this time from Lewisham. There's another case on the forum on the go too, although this one is for a 5 minute difference; harder to argue.
Yes, you certainly can submit reps on the basis of de minimis, and also point out that motorists approaching the sign only have their own clock in the car to rely on, there being no council clock visible. Hopefully, somebody will know the London Tribunals case some years ago on the same thing, where the council claimed their clock (again, not shown to motorists), is synched daily with an atomic clock. The adjudicator, in accepting the appeal said that common sense must prevail and councils accept that most car clocks are not synchronised with atomic clocks.