Branching if statements when determining the days of the week

Without using any of the date functions built into matlab, How do you take an input that is in the form xx/xx/xxxx, and displays in the command window as 4.9751e-004 (date entered was 01/01/2010) and display it back to the user as what was entered, and not the gibberish that matlab is displaying? Is there some sort of conversion that will display it properly that isn't built into matlab?

[Jared Singleton]

I figured out how to make it display the actual date rather than the numbers.

Answer 1

[Oleg Komarov]

d = datenum('08/22/1989','mm/dd/yyyy')
datestr(d,'dd-mmm-yyyy')

EDIT: no builtin date fcns

% Input: mm/dd/yyyy

s = '03/12/2008';

% Decompose into month, day, year

[m,d,y] = dataread('string',s,'%d/%d/%d');

% Determine if leap year

   if mod(y,400) == 0 || (mod(y, 100) ~= 0 && mod(y, 4) == 0);
       monthdays = [31 29 31 30 31 30 31 31 30 31 30 31];
   else
       monthdays = [31 28 31 30 31 30 31 31 30 31 30 31];
   end

% Day of year

yearday = sum(monthdays(1:m-1)) + d;

% For the day of week, starting from reference 02 Jan 0000 (Sunday)

rd = 2; % day for reference date
ty = 0:y-1; % vector of years except last one
ly = sum(mod(ty,400) == 0 | (mod(ty, 100) ~= 0 & mod(ty, 4) == 0)); % Leap years
td = numel(ty)*365 + ly + yearday - rd; % Days in between 

weekdays = {'Sun','Mon','Tue','Wed','Thu','Fri','Sat'};
disp(weekdays{mod(td,7) + 1})

[Jared Singleton]

I can't use any built in date functions within matlab unfortunately. I discovered that if I turned the input into a string I can manipulate it that way. Right now I'm trying to determine the best way to figure out the month, and through that numbered day it is within the year, and what day it actually falls on. (i.e, that 01/01/2010 is the 1st day of the year 2010 and falls on a Thursday) I don't think I can even use eomday which would help considerably.

[Oleg Komarov]

Tested, it should work for dates > 02 Jan 0000.

Also 01/01/2010 is a friday.