AMENDMENT NO. 1 TO AGREEMENT AND PLAN OF MERGER THIS AMENDMENT NO. 1 (this "Amendment") to the Agreement and Plan of Merger is made of as of June 2, 1999 by and among ABR Information Services, Inc., a Florida corporation (the "Company"), Ceridian...

                                 AMENDMENT NO. 1 TO
                            AGREEMENT AND PLAN OF MERGER

     THIS AMENDMENT NO. 1 (this "Amendment") to the Agreement and Plan of Merger
is made of as of June 2, 1999 by and among ABR Information Services, Inc., a
Florida corporation (the "Company"), Ceridian Corporation, a Delaware
corporation ("Parent"), and Spring Acquisition Corp., a wholly-owned subsidiary
of Parent and a Florida corporation ("Merger Sub").

     WHEREAS, the Company, Parent and Merger Sub have entered into that certain
Agreement and Plan of Merger, dated as of April 30, 1999 (the "Merger
Agreement");

     WHEREAS, the Company, Parent and Merger Sub wish to make certain
modifications thereto;

     NOW, THEREFORE, in consideration of the premises and for other good and
valuable consideration, the receipt and sufficiency of which are hereby
acknowledged, the parties hereto agree as follows:

     1.   Annex A to the Merger Agreement is hereby amended by deleting the
     phrase ", and at any time prior to acceptance for payment for any such
     Shares," in clause (iii) of the introductory paragraph thereof, and
     inserting in its place the phrase ", and at any time prior to expiration of
     the Offer,".

     2.   This Amendment is governed by, and shall be construed in accordance
     with, the laws of the State of Florida.

     3.   Except as herein expressly amended, the Merger Agreement is ratified
     and confirmed in all respects and shall remain in full force and effect in
     accordance with its terms.

     4.   This Amendment may be executed in two or more counterparts, each of
     which shall be deemed an original, but all of which together shall
     constitute one and the same instrument.



     IN WITNESS WHEREOF, this Agreement has been duly executed and delivered by
the duly authorized officers of the parties hereto as of the date first written
above.

                             ABR INFORMATION SERVICES, INC.



                             By:  /s/ Xxxxx X. XxxXxxxxxx
                                  -------------------------------------
                                  Name: Xxxxx X. XxxXxxxxxx
                                  Title: President and Chief Executive
                                         Officer


                             CERIDIAN CORPORATION



                             By:  /s/ Xxxx X. Xxxxxx
                                  -------------------------------------
                                  Name:  Xxxx X. Xxxxxx
                                  Title:  Vice President, General Counsel
                                          and Secretary


                             SPRING ACQUISITION CORP.



                             By:  /s/ Xxxx X. Xxxxxx
                                  -------------------------------------
                                  Name:  Xxxx X. Xxxxxx
                                  Title:  President and Chief Executive
                                          Officer