Google Calendar can be set up with a Google account.  The calendar is easy to use with a choice of colour schemes and settings.  It is possible to synchronise with a mobile phone, Microsoft Outlook,  Apple iCal and Mozilla Sunbird.

It is possible to read what is on your calendar when off line.  You have to be connected to the internet to add items and to use the automatic synchronisation between desktop diaries and Google Calendar.   According to some accessibility lists it is possible to navigate the Google calendar with JAWS and when tested with a text based browser such as WebbIE it is readable and possible to add new appointments, but not that easily due to the linear layout