The contravention occurred in Manchester therefore IMO England rules and guidance apply.
The time on the clock does not necessarily indicate the time at which the vehicle was left.
From the BB Rights etc. Booklet:
If you need to use a parking clock, you must display it on the vehicle’s dashboard or facia panel, so that the time can be seen clearly through the front windscreen. The clock should be set to show the quarter hour period during which you arrived. If there is no dashboard or facia panel in your vehicle, you must still display the clock in a place where it can be clearly read from outside the vehicle.Your options were therefore to show 19.45 or 20.00 hrs.
Contravention time: 22.49
I can't see the authority rejecting simple reps based on the above i.e. I parked between 19.45 and 20.00. The BB rules require that the clock is set 'to show the quarter-hour period during which the driver arrived' and as I arrived before 8pm I couldn't properly set the clock for that time as this would give me more than 3 hours' actual parking time. I therefore set it for 7.45pm which was before I parked. The PCN gives a time of contravention of 22.49, presumably because the CEO thought that BB clocks show the actual time of parking which, as I have explained, they do not therefore the PCN was issued in error and must be cancelled. I would also suggest that this and perhaps other CEOs are reminded of a BB holder's obligations as regards the parking clock in order to avoid similar errors occurring. For information, I have attached a link to the government website which deals with Blue Badges.
https://www.gov.uk/government/publications/the-blue-badge-scheme-rights-and-responsibilities-in-england/the-blue-badge-scheme-rights-and-responsibilities-in-england#when-you-need-to-use-a-parking-clock