National calculates rates based on a 24-hour period.
The rental rate will be calculated based on the return time agreed when picking up the vehicle.
If the vehicle is kept longer than originally planned, a daily overstay fee may be added to each rental day.
This late charge is in addition to any extra daily/weekly rates.
The rental agreement will specify if a late charge will apply.
Daily/weekly rates may also retroactively increase from the start of the rental if the vehicle is kept beyond the agreed return date and time.
The rental agreement will specify if rates are subject to retroactively change.
Within the European Union, there is a 29-minute grace period, thereafter a further full day's rental will be charged.