The upcoming activity timeline shows a list of all the events that are scheduled to happen in the future. It shows events like for example:
Emails to be sent
Mobile messages to be sent
Escalation messages to be sent
Viewing the upcoming activity timeline
Just click on any expiration and you'll see the upcoming activity timeline on the left by expanding its panel:
Viewing upcoming notifications
The upcoming notifications is the same as the upcoming activity timeline and can be found when editing an expiration:
