1.1 Effective date. This agreement is binding and is deemed effective if it is executed by all parties (the effective date). Users generally have to accept terms and conditions when they download an associated app or sign up for a website. These conditions should not be different from the terms given and read at another time by another use, unless these conditions are updated and all users are asked to approve the revised terms. Under contract law, the effective date is the date on which an agreement or transaction between or between signatories becomes mandatory. In the event of an IPO, this is the time when the shares can be traded for the first time on a stock exchange. The parties may set an effective date before the agreement is implemented. For example, to recover royalties or payments retroactive to a bygone date. Once again, Ken argues that it is clearer to use the concept of ”date of agreement” and to define concretely the periods of rights and obligations that deviate from that date. In practice, it may be more convenient to set the operating date for all rights and obligations rather than to define them individually. Sometimes the parties use the validity date to refer to a future date on which either agreement will occur. For example, a January 2004 employment contract probably refers to the date on which the worker will actually start working: the effective date was June 23, 2016. Twilio`s shares began trading that day.