Everything between agreeing a transaction and settling it.
Clearing is the process between trade and settlement: confirming the transaction, computing what each party owes, managing the exposure in between, and instructing settlement.
In many markets a central counterparty interposes itself so each side faces the clearing house rather than each other. That concentrates risk deliberately, into an institution built to hold it.
Clearing runs on its own calendar. A clearing system can be closed on a day the markets it serves are open, and payment systems — TARGET2 in the euro area, CHAPS in the United Kingdom, Fedwire in the United States — each publish their own. Those are the calendars this estate does not hold.
Clearing is the process; settlement is the completion it leads to.
The clearing house is the institution. Clearing is what it does, and some clearing happens without one.
See also clearing house · settlement date · rtgs · net settlement · settlement finality
We hold no settlement or clearing calendars. This entry defines the term and demonstrates nothing, because a near-miss borrowed from exchange closures would imply coverage that does not exist. See what we hold.