You can submit representations to the council based on de minimis. You can point out that the start time on a restriction sign for the motorist approaching it relies entirely on the time piece on his wrist or fitted to the car. If one minute was so important, then you would expect the council to provide a clock to that there was no doubt about the matter. You can say also that surely commonsense demands that PCNs are not served for such trivial contraventions when the council provide no means of knowing what time clock they are measuing against.
Of course the council will reject these reps, and may re-offer the discount. If they do, then you have the choice of taking them to the Traffic Penalty Tribunal and risk the full penalty, or just paying the discount. If they don't, then it is a total no-brainer to take them to the TPT on the basis that the contravention did not occur - de minimis. Some adjudicators are sensible, others seem to be in a rush to get to th e weekend, but thats the nature of the game, I'm afraid.
De minimis - "de minimis non curat lex" or "the law does not concern itself with trifling offences"
