A compelling event needs a date, a consequence, and an owner. Anything less is something weaker wearing the same name.
A specific date
Not soon, not this year, not before the busy season. A date. Contract expiry, regulatory deadline, system retirement, the start of a seasonal peak, an audit, a funding milestone, a person's last day.
A consequence
What actually happens if that date passes without action. Something stops working, costs are incurred, a commitment is missed, a person is left doing manual work they have said they will not continue doing.
An owner
A named person who bears that consequence. Without one, the event is a fact everyone agrees about and nobody is personally exposed to, which is functionally the same as no event at all.
A date with no consequence is a preference. A consequence with no date is a concern. Either without an owner is a topic for a meeting.