function n = datenum(arg1,arg2,arg3,h,min,s)

%DATENUM Serial date number.

%	N = DATENUM(V) converts one or more date vectors V into serial date 

%	numbers N. Input V can be an M-by-6 or M-by-3 matrix containing M full 

%	or partial date vectors respectively.  DATENUM returns a column vector

%	of M date numbers.

%

%	A date vector contains six elements, specifying year, month, day, hour, 

%	minute, and second. A partial date vector has three elements, specifying 

%	year, month, and day.  Each element of V must be a positive double 

%	precision number.  A serial date number of 1 corresponds to Jan-1-0000.  

%	The year 0000 is merely a reference point and is not intended to be 

%	interpreted as a real year.

%

%	N = DATENUM(S,F) converts text representing one or more dates to serial

%	date numbers N using format F. S can be a character array or string

%	array where each row corresponds to one date, or one dimensional cell

%	array of strings. DATENUM returns a column vector of M date numbers,

%	where M is the number of strings in S.

%

%	All of the date strings in S must have the same format F, which must be

%	composed of date format symbols according to Table 2 in DATESTR help.

%

%	Certain formats may not contain enough information to compute a date

%	number.  In those cases, hours, minutes, and seconds default to 0, days

%	default to 1, months default to January, and years default to the

%	current year. Date strings with two-character years (e.g. 19-May-88)

%	are interpreted to be within the 100 years centered around the current

%	year.

%

%	N = DATENUM(S,F,P) or N = DATENUM(S,P,F) uses the specified format F

%	and the pivot year P to determine the date number N, from S. 

%   The pivot year is the starting year of the 100-year range in 

%	which a two-character year resides.  The default pivot year is the 

%	current year minus 50 years.

%

%	N = DATENUM(Y,MO,D) and N = DATENUM([Y,MO,D]) return the serial date

%	numbers for corresponding elements of the Y,MO,D (year,month,day)

%	arrays. Y, MO, and D must be arrays of the same size (or any can be a

%	scalar).

%

%	N = DATENUM(Y,MO,D,H,MI,S) and N = DATENUM([Y,MO,D,H,MI,S]) return the

%	serial date numbers for corresponding elements of the Y,MO,D,H,MI,S

%	(year,month,day,hour,minute,second) arrays.  The six arguments must be

%	arrays of the same size (or any can be a scalar).

%

%   N = DATENUM(V) converts date represented as date vector (as defined by

%   DATEVEC) V into a serial date number.

%

%	N = DATENUM(S) converts date represented as text S into a serial date

%	number. S must be in one of the date formats 0,1,2,6,13,14,15,16,23 as

%	defined by DATESTR. This calling syntax is provided for backward

%	compatibility, and is significantly slower than the syntax which

%	specifies the format. If the format is known, the N =

%	DATENUM(S,F) syntax should be used.

%

%	N = DATENUM(S,P) converts date represented as text S, using pivot year

%	P. If the format is known, the N = DATENUM(S,F,P) or N = DATENUM(S,P,F)

%	syntax should be used.

%

%	Note:  The vectorized calling syntax can offer significant performance

%	improvement for large arrays.

%

%	Examples:

%		n = datenum('19-May-2000') returns n = 730625. 

%		n = datenum(2001,12,19) returns n = 731204. 

%		n = datenum(2001,12,19,18,0,0) returns n = 731204.75. 

%		n = datenum('19.05.2000','dd.mm.yyyy') returns n = 730625.

%

%	See also NOW, DATESTR, DATEVEC, DATETICK.

%   Copyright 1984-2019 The MathWorks, Inc.

narginchk(1, 6); 

% Shallow adoption of string

arg1 = matlab.internal.datatypes.stringToLegacyText(arg1); 

% parse input arguments

isdatestr = ~isnumeric(arg1); 

isdateformat = false; 

if nargin == 2 

    arg2 = matlab.internal.datatypes.stringToLegacyText(arg2); 

    isdateformat = ischar(arg2); 

elseif nargin == 3 

    arg2 = matlab.internal.datatypes.stringToLegacyText(arg2);

    arg3 = matlab.internal.datatypes.stringToLegacyText(arg3);

    isdateformat = [ischar(arg2), ischar(arg3)];

end 

if isdatestr && isempty(arg1) 

    n = zeros(0,1);

	warning(message('MATLAB:datenum:EmptyDate'));

    return;

end 

% try to convert date character vector or date vector to a date number

try 

    switch nargin 

        case 1  

            if isdatestr 

                n = datenummx(datevec(arg1)); 

            elseif ((size(arg1,2)==3) || (size(arg1,2)==6)) && ... 

                    any(abs(arg1(:,1) - 2000) < 10000) 

                n = datenummx(arg1); 

            else

                n = arg1;

            end 

        case 2 

            if isdateformat 

                if ischar(arg1) 

					arg1 = cellstr(arg1); 

                end 

                if ~iscellstr(arg1) 

                    %At this point we should have a cell array.  Otherwise error.

                    error(message('MATLAB:datenum:NotAStringArray'));

                end 

                if isempty(arg2) 

                    n = datenummx(datevec(arg1));

                else 

                    n = dtstr2dtnummx(arg1,matlab.internal.datetime.cnv2icudf(arg2));              

                end 

            else

                n = datenummx(datevec(arg1,arg2));

            end 

        case 3

			if any(isdateformat)

				if isdateformat(1) 

					format = arg2;

					pivot = arg3;

				elseif isdateformat(2)

					format = arg3;

					pivot = arg2;

				end

				if ischar(arg1)

					arg1 = cellstr(arg1);

				end

                if ~iscellstr(arg1)

                    %At this point we should have a cell array.  Otherwise error.

                    error(message('MATLAB:datenum:NotAStringArray'));

                end

				icu_dtformat = matlab.internal.datetime.cnv2icudf(format);

				showyr =  strfind(icu_dtformat,'y'); 

                if ~isempty(showyr)

                    wrtYr =  numel(showyr);

                    checkYr = diff(showyr);

                    if any(checkYr~=1)

                        error(message('MATLAB:datenum:YearFormat'));

                    end

                    switch wrtYr

                        case 4

                            icu_dtformat = strrep(icu_dtformat,'yyyy','yy');

                        case 3

                            icu_dtformat = strrep(icu_dtformat,'yyy','yy');

                    end

                end

                if (isempty(format))

                    n = datenummx(datevec(arg1,pivot));

                else

                    if (isempty(pivot))

                        n = dtstr2dtnummx(arg1,icu_dtformat);

                    else

                        n = dtstr2dtnummx(arg1,icu_dtformat,pivot);

                    end

                end

            else

                verifySizes(arg1,arg2,arg3);

                n = datenummx(arg1,arg2,arg3);

			end

        case 6

            verifySizes(arg1,arg2,arg3,h,min,s);

            n = datenummx(arg1,arg2,arg3,h,min,s);

        otherwise

            error(message('MATLAB:datenum:Nargin'));

    end 

catch exception   

    if (nargin == 1 && ~isdatestr)

        identifier = 'MATLAB:datenum:ConvertDateNumber';

    elseif (nargin == 1 && isdatestr) || (isdatestr && any(isdateformat))

        identifier = 'MATLAB:datenum:ConvertDateString';

    elseif (nargin > 1) && ~isdatestr && ~any(isdateformat)

        identifier = 'MATLAB:datenum:ConvertDateVector';

    else

        identifier = exception.identifier;

    end

    newExc = MException( identifier,'%s',getString(message('MATLAB:datenum:Failed')));

    newExc = newExc.addCause(exception);

    throw(newExc);

end