A computer-implemented method provides location-sensitive and time-sensitive calendaring to a wireless device, such as a cell phone, pager, PDA, etc. A user's calendar is maintained with a number of appointments, start times and end times for the appointments, meeting place and a list of attendees for the appointments. When the present time reading is within a predetermined minimum of a meeting start time of an appointment of a calendar user, the location of the user is determined based on the location of the wireless device. The location of the meeting place is also determined. Using historical data (of the user or others), the estimated time of arrival of the user at the meeting place is determined. If the estimated time of arrival is after the meeting start time, then a late message may be sent to the user and/or to the other meeting attendees.