You can find the check-in and check-out times on your Trip page when clicking on your stay, under the section 'Know before you go':

You can also find these on your Bookings Page in the 'Get into your stay' and the 'Check out from your stay' sections:

If you wish to change these times, please contact the accommodation directly to request early check-in or late check out. Please note this may be available at an extra cost. The contact details for your accommodation can be found on the 'Get into your stay' section.