On 09/03/2019 19:36, ARW wrote:
Stick a days visitors parking voucher in the windscreen at 1pm and it
must be valid until 1pm the next day.

A day is 24 hours.

I was going to say "look at the small print" but even so, if it wasn't
specified at the point of sale, nor were you drawn attention to them,
then face value maybe what matters.

Is this a private car park, or a London authority car park? One will
have to prove their case, the other simply say a byelaw is in place
where ignorance of the law is no defence.