anchor.diff:    procedure,pass(self),public :: yearday
   
     ! private methods
  -  procedure :: addMilliseconds
  -  procedure :: addSeconds
  -  procedure :: addMinutes
  -  procedure :: addHours
  -  procedure :: addDays
  +  procedure,pass(self),private :: addMilliseconds
  +  procedure,pass(self),private :: addSeconds
  +  procedure,pass(self),private :: addMinutes
  +  procedure,pass(self),private :: addHours
  +  procedure,pass(self),private :: addDays
   
     ! operator overloading procedures
  -  procedure,private :: datetime_plus_timedelta
  -  procedure,private :: datetime_minus_datetime
  -  procedure,private :: datetime_minus_timedelta 
  -  procedure,private :: eq
  -  procedure,private :: neq
  -  procedure,private :: gt
  -  procedure,private :: ge
  -  procedure,private :: lt
  -  procedure,private :: le
  -
  -  generic :: operator(+)  => datetime_plus_timedelta
  +  procedure,pass(d0),private :: datetime_plus_timedelta
  +  procedure,pass(d0),private :: timedelta_plus_datetime
  +  procedure,pass(d0),private :: datetime_minus_datetime
  +  procedure,pass(d0),private :: datetime_minus_timedelta 
  +  procedure,pass(d0),private :: eq
  +  procedure,pass(d0),private :: neq
  +  procedure,pass(d0),private :: gt
  +  procedure,pass(d0),private :: ge
  +  procedure,pass(d0),private :: lt
  +  procedure,pass(d0),private :: le
  +
  +  generic :: operator(+)  => datetime_plus_timedelta,&
  +                             timedelta_plus_datetime
     generic :: operator(-)  => datetime_minus_datetime,&
                                datetime_minus_timedelta
     generic :: operator(==) => eq
  
positive.code: ! Copyright (c) 2013-2016, Wavebit Scientific LLC
  ! All rights reserved.
  ! 
  ! Licensed under the BSD-3 clause license. See LICENSE for details.
  !
  module mod_datetime
  !=======================================================================
  
negative.code:   module procedure :: datetime_constructor
  endinterface datetime
  
  !interface operator(+)
  !  module procedure :: timedelta_plus_datetime
  !endinterface
  
  !=======================================================================
  contains
  