If you have a time delay on both the Jump to event action and the action that it's jumping to (see screenshot below), then the branch with the Jump to Event action will take priority and fire.
In the example below the Jump to Event action has a time delay of 30 min, while the action it's jumping to ("Send follow-up email), has a delay of 90 min. In this case, the contacts following the branch of Jump to Event action ("B") will have their follow-up email sent out 30 min after the previous decision of downloading the guide.
The contacts who follow the "A" branch will have their follow-up email sent out 90 min after their decision of downloading the guide.
Under the Decision branch, you have the option of Page hits (i.e if the lead has visited a page). These hits are counted as "anytime" and not "within one session". The current system does not have the possibility to distinguish between page visits in the same session or in different sessions.
You can perform actions in a campaign based on a date, e.g send out an email 2 days before an expiry date or send out yearly birthday wishes to your contacts if you have their date of birth.