Events can be scheduled for the future using deliverAt or deliverAfter (see options in the docs: https://trigger.dev/docs/sdk/io/sendevent).
You can programatically cancel these using cancelEvent(): https://trigger.dev/docs/sdk/triggerclient/instancemethods/cancel-event
We should add a Cancel button to the top-right of an Event page, if that event has not been delivered yet.
This event hasn't been delivered yet.

Position of cancel button

From SyncLinear.com | TRI-1879