If other users are invited to the Meeting, changes to your reply will automatically appear in their Agendas as well. If the Meeting's owner changes the time or date of the Meeting, it will appear as a new Meeting in your In-tray, thereby replacing the old Meeting.
Response options:
After selecting a response, you can indicate that you would prefer another time for the meeting by selecting the I would prefer another time check box.
Select how you would like the meeting time to appear in your agenda by selecting either Free or Busy from the Show time as drop-down list. For example, if you are not going to attend the meeting but do not want others to book you during that time, you can combine the I will not attend response with Show time as: Busy.