You can set up automatic periodic session saving using the Scheduled tab of the Sessions dialog.
Figure 5.2 The Scheduled tab of the Sessions dialog
Select or deselect Save session using this schedule to switch automatic saving on or off.
You can select days in the week and a time of the day to do the saving.
When the saving time is reached, the system raises the Save Session dialog and waits for some period of time to allow you to change the settings, cancel the saving, or confirm it. If the period of time passes without you cancelling, the system proceeds to do the saving. The period of time to wait is set by the Allow cancellation option.
Press the Defaults... button to raise the Save Session dialog which allows you to set the parameters for the saving. When you confirm, it does not save the session, but remembers the settings and uses them when doing the automatic saving.