SUBROUTINE TIMDIF(BEGT,ENDT,IDIF)
C          This computes the time difference in units of centi-secs
C          (i.e. 100th secs) as ENDT - BEGT, where ___T are integer dim 4
C          with elements yyyy, mmdd, hhmm and centiseconds respectively.
 
      INTEGER BEGT(4),ENDT(4),BEGMO,BEGDA,BEGHR,BEGMI,
     +                        ENDMO,ENDDA,ENDHR,ENDMI
      DOUBLE PRECISION IDIF
 
      BEGMO = BEGT(2)/100
      BEGDA = BEGT(2)     - BEGMO*100
      BEGHR = BEGT(3)/100
      BEGMI = BEGT(3)     - BEGHR*100
 
      ENDMO = ENDT(2)/100
      ENDDA = ENDT(2)     - ENDMO*100
      ENDHR = ENDT(3)/100
      ENDMI = ENDT(3)     - ENDHR*100
 
C          Calculate the number centi-seconds difference:
      IDIF = DBLE( (ENDT(4)-BEGT(4)) )
 
C          Include the number minutes difference in units of csecs
      IDIF = IDIF + DBLE( (ENDMI-BEGMI) ) * 6000D0
 
C          Include hours difference
      IDIF = IDIF + DBLE( (ENDHR-BEGHR) ) * 360000D0
 
C          Calculate days and years difference:
      CALL HOURS(BEGT(1),BEGMO,BEGDA,IBEGH)
      CALL HOURS(ENDT(1),ENDMO,ENDDA,IENDH)
C          Subroutine HOURS computes the number of hours since 1920;
C          e.g. 0100 1 Jan 1921 entered would return IBEGH = 1.  HOURS
C          is part of the NCAR library routines.
      IDIF = IDIF + DBLE( (IENDH-IBEGH) ) * 360000D0
 
      RETURN
      END