SECURITIES & EXCHANGE COMMISSION
                             Washington, D.C. 20549
                             ----------------------

                                  SCHEDULE 13G*
                                 (Rule 13d-102)

             INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT
           TO RULES 13d-1(b), (c) AND (d) AND AMENDMENTS THERETO FILED
                              PURSUANT TO 13d-2(b)

                              CERIDIAN CORPORATION
                                (Name of Issuer)

                                  Common Stock
                         (Title of Class of Securities)

                                    156779100
                                 (CUSIP Number)

                               December 11, 2006**
             (Date of event which requires filing of this statement)



     Check the appropriate box to designate the rule pursuant to which this
Schedule 13G is filed:


     [x] Rule 13d-1(b)
     [ ] Rule 13d-1(c)
     [ ] Rule 13d-1(d)





                           (Page 1 of 10 Pages)
----------------
     *The remainder of this cover page shall be filled out for a reporting
person's initial filing on this form with respect to the subject class of
securities, and for any subsequent amendment containing information which would
alter the disclosures provided in a prior cover page.

     The information required in the remainder of this cover page shall not be
deemed to be "filed" for purposes of Section 18 of the Securities Exchange Act
of 1934 ("Act") or otherwise subject to the liabilities of that section of the
Act but shall be subject to all other provisions of the Act (however, see the
Notes). ** The Reporting Persons have elected to file this Schedule 13G in
advance of the required filing date.




CUSIP No. 156779100                 13G                    Page 2 of 12 Pages

----------------------------------------------------------------------------
     (1)    NAMES OF REPORTING PERSONS
            I.R.S. IDENTIFICATION NO.
            OF ABOVE PERSONS (ENTITIES ONLY)
                                       Pershing Square Capital Management, L.P.
-----------------------------------------------------------------------------
     (2)    CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP **
                                                                  (a)  [ ]
                                                                  (b)  [X]
-----------------------------------------------------------------------------
     (3)    SEC USE ONLY
-----------------------------------------------------------------------------
     (4)    CITIZENSHIP OR PLACE OF ORGANIZATION
                            Delaware
-----------------------------------------------------------------------------
NUMBER OF      (5)  SOLE VOTING POWER
                                                -0-
SHARES         --------------------------------------------------------------

BENEFICIALLY   (6)  SHARED VOTING POWER
                                                 15,724,334
OWNED BY       --------------------------------------------------------------

EACH           (7)  SOLE DISPOSITIVE POWER
                                                -0-
REPORTING      --------------------------------------------------------------

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                                                 15,724,334
-----------------------------------------------------------------------------
     (9)    AGGREGATE AMOUNT BENEFICIALLY OWNED
            BY EACH REPORTING PERSON
                                                 15,724,334
-----------------------------------------------------------------------------
     (10)   CHECK BOX IF THE AGGREGATE AMOUNT
            IN ROW (9) EXCLUDES CERTAIN SHARES **                       [ ]
-----------------------------------------------------------------------------
     (11)   PERCENT OF CLASS REPRESENTED
            BY AMOUNT IN ROW (9)
                                                11.3%

-----------------------------------------------------------------------------
     (12)   TYPE OF REPORTING PERSON **
                                                 IA
-----------------------------------------------------------------------------




CUSIP No. 156779100                 13G                    Page 3 of 12 Pages

----------------------------------------------------------------------------
     (1)    NAMES OF REPORTING PERSONS
            I.R.S. IDENTIFICATION NO.
            OF ABOVE PERSONS (ENTITIES ONLY)
                                                   PS Management GP, LLC
-----------------------------------------------------------------------------
     (2)    CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP **
                                                                  (a)  [ ]
                                                                  (b)  [X]
-----------------------------------------------------------------------------
     (3)    SEC USE ONLY
-----------------------------------------------------------------------------
     (4)    CITIZENSHIP OR PLACE OF ORGANIZATION
                            Delaware
-----------------------------------------------------------------------------
NUMBER OF      (5)  SOLE VOTING POWER
                                                -0-
SHARES         --------------------------------------------------------------

BENEFICIALLY   (6)  SHARED VOTING POWER
                                                 15,724,334
OWNED BY       --------------------------------------------------------------

EACH           (7)  SOLE DISPOSITIVE POWER
                                                -0-
REPORTING      --------------------------------------------------------------

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                                                 15,724,334
-----------------------------------------------------------------------------
     (9)    AGGREGATE AMOUNT BENEFICIALLY OWNED
            BY EACH REPORTING PERSON
                                                 15,724,334

-----------------------------------------------------------------------------
     (10)   CHECK BOX IF THE AGGREGATE AMOUNT
            IN ROW (9) EXCLUDES CERTAIN SHARES **                       [ ]
-----------------------------------------------------------------------------
     (11)   PERCENT OF CLASS REPRESENTED
            BY AMOUNT IN ROW (9)
                                                11.3%
-----------------------------------------------------------------------------
     (12)   TYPE OF REPORTING PERSON **
                                                 OO
-----------------------------------------------------------------------------




CUSIP No. 156779100                 13G                    Page 4 of 12 Pages

----------------------------------------------------------------------------
     (1)    NAMES OF REPORTING PERSONS
            I.R.S. IDENTIFICATION NO.
            OF ABOVE PERSONS (ENTITIES ONLY)
                             Pershing Square GP, LLC
-----------------------------------------------------------------------------
     (2)    CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP **
                                                                  (a)  [ ]
                                                                  (b)  [X]
-----------------------------------------------------------------------------
     (3)    SEC USE ONLY
-----------------------------------------------------------------------------
     (4)    CITIZENSHIP OR PLACE OF ORGANIZATION
                            United States
-----------------------------------------------------------------------------
NUMBER OF      (5)  SOLE VOTING POWER
                                                -0-
SHARES         --------------------------------------------------------------

BENEFICIALLY   (6)  SHARED VOTING POWER
                                                 7,128,122
OWNED BY       --------------------------------------------------------------

EACH           (7)  SOLE DISPOSITIVE POWER
                                                -0-
REPORTING      --------------------------------------------------------------

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                                                 7,128,122
-----------------------------------------------------------------------------

     (9)    AGGREGATE AMOUNT BENEFICIALLY OWNED
            BY EACH REPORTING PERSON
                                                 7,128,122
-----------------------------------------------------------------------------
     (10)   CHECK BOX IF THE AGGREGATE AMOUNT
            IN ROW (9) EXCLUDES CERTAIN SHARES **                       [ ]
-----------------------------------------------------------------------------
     (11)   PERCENT OF CLASS REPRESENTED
            BY AMOUNT IN ROW (9)
                                                5.1%
-----------------------------------------------------------------------------
     (12)   TYPE OF REPORTING PERSON **
                                                 IA
-----------------------------------------------------------------------------




CUSIP No. 156779100                  13G                   Page 5 of 12 Pages

----------------------------------------------------------------------------
     (1)    NAMES OF REPORTING PERSONS
            I.R.S. IDENTIFICATION NO.
            OF ABOVE PERSONS (ENTITIES ONLY)
                                William A. Ackman
-----------------------------------------------------------------------------
     (2)    CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP **
                                                                  (a)  [ ]
                                                                  (b)  [X]
-----------------------------------------------------------------------------
     (3)    SEC USE ONLY
-----------------------------------------------------------------------------
     (4)    CITIZENSHIP OR PLACE OF ORGANIZATION
                            United States
-----------------------------------------------------------------------------
NUMBER OF      (5)  SOLE VOTING POWER
                                                -0-
SHARES         --------------------------------------------------------------

BENEFICIALLY   (6)  SHARED VOTING POWER
                                                 15,724,334
OWNED BY       --------------------------------------------------------------

EACH           (7)  SOLE DISPOSITIVE POWER
                                                -0-
REPORTING      --------------------------------------------------------------

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                                                 15,724,334
-----------------------------------------------------------------------------

     (9)    AGGREGATE AMOUNT BENEFICIALLY OWNED
            BY EACH REPORTING PERSON
                                                 15,724,334
-----------------------------------------------------------------------------
     (10)   CHECK BOX IF THE AGGREGATE AMOUNT
            IN ROW (9) EXCLUDES CERTAIN SHARES **                       [ ]
-----------------------------------------------------------------------------
     (11)   PERCENT OF CLASS REPRESENTED
            BY AMOUNT IN ROW (9)
                                                11.3%
-----------------------------------------------------------------------------
     (12)   TYPE OF REPORTING PERSON **
                                                 IN
-----------------------------------------------------------------------------




CUSIP No. 156779100                 13G                    Page 6 of 12 Pages

Item 1(a).     Name of Issuer:

     The name of the issuer is Ceridian Corporation (the "Company").

Item 1(b).     Address of Issuer's Principal Executive Offices:

     The Company's principal executive offices are located at 3311 East Old
Shakopee Road, Minneapolis, Minnesota 55425.

Item 2(a).     Name of Person Filing:

     This statement is filed by:

          (i)       Pershing Square Capital Management, L.P., a Delaware limited
                    partnership (the "Investment Manager"), which serves as
                    investment advisor to Pershing Square, L.P. ("Pershing
                    Square"), a Delaware limited partnership, Pershing Square
                    II, L.P. ("Pershing Square II"), a Delaware limited
                    partnership, and Pershing Square International, Ltd.
                    ("Pershing Square International"), a Cayman Islands exempted
                    company, with respect to the shares of Common Stock (as
                    defined in Item 2(d) below), held for the account of
                    Pershing Square (6,981,363 shares), Pershing Square II
                    (146,759 shares), and Pershing Square International
                    (8,596,212 shares), respectively;

          (ii)      PS Management GP, LLC, a Delaware limited liability company
                    ("PS Management"), which serves as the general partner of
                    the Investment Manager;

         (iii)      Pershing Square GP, LLC (the "General Partner"), a Delaware
                    limited liability company, which serves as the general
                    partner of each of Pershing Square and Pershing Square II;
                    and

         (iv)       William A. Ackman, an individual ("Mr. Ackman"), who serves
                    as the managing member of each of PS Management and the
                    General Partner.


                  The foregoing persons are hereinafter sometimes collectively
referred to as the "Reporting Persons." Any disclosures herein with respect to
persons other than the Reporting Persons are made on information and belief
after making inquiry to the appropriate party. Each of Pershing Square, Pershing
Square II, and Pershing Square International disclaims beneficial ownership of
any shares of Common Stock.




CUSIP No. 156779100                 13G                    Page 7 of 12 Pages

Item 2(b).     Address of Principal Business Office or, if None, Residence:

     The address of the business office of each of the Reporting Persons is 888
Seventh Avenue, 29th Floor, New York, New York 10019.

Item 2(c).     Citizenship:

     Investment Manager is a limited partnership organized under the laws of the
State of Delaware. PS Management is a limited liability company organized under
the laws of the State of Delaware. The General Partner is a limited liability
company organized under the laws of the State of Delaware. Mr. Ackman is a
United States citizen.

Item 2(d).     Title of Class of Securities:

     Ceridian Corporation, common stock, $0.01 par value per share (the "Common
Stock").

Item 2(e).  CUSIP Number:
     156779100.

Item 3. If this statement is filed pursuant to Rules 13d-1(b) or 13d-2(b) or
(c), check whether the person filing is a:

          (a) [ ] Broker or dealer registered under Section 15 of the Act,

          (b) [ ] Bank as defined in Section 3(a)(6) of the Act,

          (c) [ ] Insurance Company as defined in Section 3(a)(19) of the Act,

          (d) [ ] Investment Company registered under Section 8 of the
                  Investment Company Act of 1940,

          (e) [x] Investment Adviser in accordance with Rule
                  13d-1(b)(1)(ii)(E),(1)

          (f) [ ] Employee Benefit Plan or Endowment Fund in accordance with
                  13d-1(b)(1)(ii)(F),

          (g) [x] Parent Holding Company or control person in accordance with
                  Rule 13d-1(b)(1)(ii)(G),(2)

          (h) [ ] Savings Association as defined in Section 3(b) of the
                  Federal Deposit Insurance Act,

          (i) [ ] Church Plan that is excluded from the definition of an
                  investment company under Section 3(c)(14) of the Investment
                  Company Act of 1940,


---------------------------------
(1) With respect to the Investment Manager and the General Partner.
(2) With respect to PS Management and Mr. Ackman.




CUSIP No. 156779100                  13G                   Page 8 of 12 Pages

          (j) [ ] Group, in accordance with Rule 13d-1(b)(1)(ii)(J).

     If this statement is filed pursuant to Rule 13d-1(c), check the box.[ ]

Item 4.   Ownership.

         A. Pershing Square Capital Management, L.P.

              (a) May be deemed to have beneficially owned: 15,724,334 shares of
Common Stock.

              (b) Percent of class: 11.3% The percentages used herein and in the
rest of Item 4 are calculated based upon the 139,124,108 shares of Common Stock
issued and outstanding as of October 31, 2006 as reflected in the Company's Form
10-Q, dated November 11, 2006.

              (c) Number of shares as to which such person may be deemed to
have:
                (i) Sole power to vote or direct the vote: -0-
               (ii) Shared power to vote or direct the vote: 15,724,334
              (iii) Sole power to dispose or direct the disposition: -0-
               (iv) Shared power to dispose or direct the disposition:
                    15,724,334

         B. PS Management GP, LLC

              (a) May be deemed to have beneficially owned: 15,724,334 shares
of Common Stock.

              (b) Percent of class: 11.3%

              (c) Number of shares as to which such person may be deemed to
have:
                (i) Sole power to vote or direct the vote: -0-
               (ii) Shared power to vote or direct the vote: 15,724,334
              (iii) Sole power to dispose or direct the disposition: -0-
               (iv) Shared power to dispose or direct the disposition:15,724,334

         C. Pershing Square GP, LLC

              (a) May be deemed to have beneficially owned: 7,128,122 shares of
                  Common Stock.

              (b) Percent of class: 5.1%

              (c) Number of shares as to which such person may be deemed to
have:
                (i) Sole power to vote or direct the vote: -0-
               (ii) Shared power to vote or direct the vote: 7,128,122
              (iii) Sole power to dispose or direct the disposition: -0-
               (iv) Shared power to dispose or direct the disposition: 7,128,122

         D. William A. Ackman

              (a) May be deemed to have beneficially owned: 15,724,334 shares of
Common Stock.




CUSIP No. 156779100                  13G                   Page 9 of 12 Pages

              (b) Percent of class: 11.3%

              (c) Number of shares as to which such person may be deemed to
have:
                (i) Sole power to vote or direct the vote: -0-
               (ii) Shared power to vote or direct the vote: 15,724,334
              (iii) Sole power to dispose or direct the disposition: -0-
               (iv) Shared power to dispose or direct the disposition:15,724,334




CUSIP No. 156779100                 13G                   Page 10 of 12 Pages

Item 5.     Ownership of Five Percent or Less of a Class.

     Not applicable.

Item 6.     Ownership of More than Five Percent on Behalf of Another Person.

         Investment Manager, in its capacity as the investment advisor to
Pershing Square, Pershing Square II, and Pershing Square International, has the
power to direct the investment activities of each of Pershing Square, Pershing
Square II, and Pershing Square International. PS Management is the general
partner of the Investment Manager. The General Partner, in its capacity as the
general partner to Pershing Square and Pershing Square II, has the power to
direct the investment activities of each of Pershing Square and Pershing Square
II. Each of the Investment Manager and the General Partner is a registered
investment advisor under the Investment Advisors Act of 1940. Mr. Ackman is the
managing member of each of PS Management and the General Partner.

Item 7.     Identification and Classification of the Subsidiary Which Acquired
the Security Being Reported on by the Parent Holding Company or Control Person.

     Not applicable.

Item 8.  Identification and Classification of Members of the Group.

     See Item 2.

Item 9.  Notice of Dissolution of Group.

     Not applicable.

Item 10.  Certification.

     Each of the Reporting Persons hereby makes the following certification:

          By signing below I certify that, to the best of my knowledge and
belief, the securities referred to above were not acquired and are not held for
the purpose of or with the effect of changing or influencing the control of the
issuer of the securities and were not acquired and are not held in connection
with or as a participant in any transaction having that purpose or effect.




CUSIP No. 156779100                13G                    Page 11 of 12 Pages

SIGNATURES

After reasonable inquiry and to the best of our knowledge and belief, the
undersigned certify that the information set forth in this statement is true,
complete and correct.


DATED:  December 20, 2006

                               PERSHING SQUARE CAPITAL MANAGEMENT, LP.
                               By:     PS Management GP, LLC,
                                       its General Partner


                               By:     /s/ William A. Ackman
                                       --------------------------
                                       William A. Ackman,
                                       Managing Member

                               PS MANAGEMENT GP, LLC


                               By:     /s/ William A. Ackman
                                       --------------------------
                                       William A. Ackman,
                                       Managing Member

                               PERSHING SQUARE GP, LLC


                               By:     /s/ William A. Ackman
                                       --------------------------
                                       William A. Ackman,
                                       Managing Member

                               WILLIAM A. ACKMAN

                                       /s/ William A. Ackman
                                       --------------------------




CUSIP No. 156779100                13G                    Page 12 of 12 Pages

                                 EXHIBIT 1

                         JOINT FILING STATEMENT
                          PURSUANT TO RULE 13d-1(k)


           The undersigned acknowledge and agree that the foregoing statement on
Schedule 13G, is filed on behalf of each of the undersigned and that all
subsequent amendments to this statement on Schedule 13G, shall be filed on
behalf of each of the undersigned without the necessity of filing additional
joint filing statements. Each of the undersigned acknowledges that each shall be
responsible individually for the timely filing of such amendments, and for the
completeness and accuracy of the information concerning such person contained
therein, but shall not be responsible for the completeness and accuracy of the
information concerning the others, except to the extent that such person knows
or has reason to believe that such information is inaccurate.


DATED:  December 20, 2006     PERSHING SQUARE CAPITAL MANAGEMENT, LP.
                              By:     PS Management GP, LLC,
                                      its General Partner


                              By:     /s/ William A. Ackman
                                      --------------------------
                                      William A. Ackman,
                                      Managing Member

                              PS MANAGEMENT GP, LLC


                              By:     /s/ William A. Ackman
                                      --------------------------
                                      William A. Ackman,
                                      Managing Member

                              PERSHING SQUARE GP, LLC


                              By:     /s/ William A. Ackman
                                      --------------------------
                                      William A. Ackman,
                                      Managing Member

                              WILLIAM A. ACKMAN

                              /s/ William A. Ackman
                              --------------------------