You can export both customer and appointment data to an Excel file. We also have an iCalendar (ICS) export feature which you can use with almost all calendar softwares out there. We even even a live feed which will automatically keep an up to date copy of your appointments in a special calendar in your favorite calendar software. We also have a vCard export feature to fill your address book software.
Appointment data: go to "my settings" > "links" and you'll find CSV (Excel compatible) as well as ICS (iCalendar format, compatible with Outlook, iCal, Sunbird, Google Calendar...) export links.
Client data: go to "management" > "registered clients" and you'll find a CSV and VCF (vCard, compatible with address book softwares) links.
Note: you must be an administrator for the account in order to see this page at all.