I have a table of meetings that contains meeting information. However some meetings are rescheduled for a new time or date. These meetings appear twice or more in the dataset.   I want to keep only the information for the last meeting, however I would like to store the information on how many times the meeting have been rescheduled. How can I achieve this in SAS?   The key data that I have is: MeetingID                          CustID                 Meetingdate    MeetingTime Timestamp at booking         ID                            Date              Time     What I want: CustID                      Meetingdate          Meetingtime        Number of reschedules ID                                   Date                       Time                     #   I realize that if a meeting is rescheduled it can still appear twice, however this is a only a minor issue. If there is a smart solution to allow to count rescheduled meetings say within +-15 days this would be excellent, but not a necessary requirement.    CustID                      Meetingdate          Meetingtime        Number of reschedules on this date        Meetings within +-15 days ID                                   Date                       Time                          #                                                                     #   As I am new to SAS i'm not able to achieve this by code, hopefully someone has a smart solution. I'm using SAS EG 8.2.       ... View more