You can open appointments you've previously created and make changes.
Open the appointment.
When you open a repeating item, Outlook Web App opens only the currently selected date, not the series. To make changes to a repeating series, click Edit Series in the toolbar or the edit the series link below the toolbar.
Make your changes in the correct boxes, for example, the Subject or Location boxes. To change the date or time, use the Start time and End time lists.
Click Save and Close.
What if I want to know more?