These data indicate when the contract or part of it must have legal effect if these data deviate from the contract and/or the dates of signature. When a contract begins on the day all parties sign it, it is a conditional effective date. A contract could also begin after important documents have been filed with the state or the date a licence is issued. To understand the difference between the signing of a contract and the entry into force of a contract, there are two important notions to know: the date of entry into force and the date of performance. Sometimes the parties use the effective date to refer to a future date when either agreement arises. .