Dependent Events
Preceden's Dependent feature lets you specify that one event should start when another event ends.
For example, in this timeline Event B starts when Event A ends:

There are two ways to go about this:
Manually Set the Start Date for Event B
With this approach, you type Event B's start date yourself: June 8, 2022, the day after Event A ends.

Mark Event B as a Dependent of Event A
To do this, click Event B on your timeline (or its name in the list below the timeline) to open the Update Event dialog, check the Dependent box, then select Event A from the dropdown:

The advantage is that when you change Event A's dates, Event B's dates update automatically so it still starts when Event A ends:

FAQs
How are dependents and connections related?
When you make Event B a dependent of Event A, Preceden also adds a visual connection between the two events by default:

If you would rather not show that line, open Event B's More Options and remove Event A from the Connected Events field.
Does connecting two events make one of them a dependent?
No. A connection is a line drawn between two events and nothing more: it has no bearing on either event's dates. The Dependent box is the only setting that makes one event's start date follow another event's end date, so connecting events in Connected Events leaves both of their dates exactly where you set them.
If you aren't sure which one an event has, open it and look at its Start Date field. On a dependent, that field is a menu naming the event this one starts after. On an event that is merely connected, Start Date still holds the date you typed, and the other event appears as a tag in Connected Events under More Options.
What happens if I delete Event A?
Preceden gives Event B a fixed start date matching Event A's end date, or Event A's start date if it had no end date.