From the T&A Events tab toolbar, click Mode.

Edit the following parameters:
# of Days - Enter a number to indicate the duration between current
event and previous event.
Process Days - Select the process days to indicate the name of the process
days.
Dependency - Select the dependency date of the current event from the
drop-down list.
Look-up Working Day - Select Yes or No from the drop-down list to indicate
whether the duration need to look up working day.