89
Difference?
 <Assertion xmlns="urn:oasis:names:tc:SAML:2.0:assertion"
                       Version="2.0"
                       IssueInstant="2005-01-31T12:00:00Z"
                       ID="abe567de6">
         <Issuer>http://www.AirlineInc.com</Issuer>
         <Subject>
                <NameID Format="urn:oasis:names:tc:1.1:nameid-format:emailAddress">
                         j.doe@acompany.com
                </NameID>
                <SubjectConfirmation Method="urn:oasis:names:tc:SAML:2.0:cm:bearer">
                           <SubjectConfirmationData Recipient="https://www.CarRentalInc.com"
                                                                       NotOnOrAfter="2005-01-31T13:00:00Z">
                           </SubjectConfirmationData>
                </SubjectConfirmation>
         </Subject>
         <Conditions NotBefore="2005-01-31T12:00:00Z"
                              NotOnOrAfter="2005-01-31T13:00:00Z"/>
         <AuthnStatement AuthnInstant="2005-01-29T09:32:00Z">
             …
         </AuthnStatement>
     </Assertion>
The assertion is valid only before this datetime. This datetime may be some time in the future.
The presenter must present himself before this datetime. This datetime is usually pretty soon.