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.

A day IS 24 hours but I suspect in this case it is the 24 hours(ish)
from midnight( well 0.0:00...1) to midnight( well 23.59:99...9 ) later
that same day