Make a loop with multiple conditions the correct way

a = 1982
b = 3
c = 25
r = 4468
thirtydays = [4 6 9 11]
thirthyonedays = [1 3 5 7 8 10 12]
normalyears = [1971 1973 1974 1975 1977 1978 1979 1981 1982 1983 1985 1986 1987 1989 1990 1991 1993 1994 1995 1997 1998 1999 2001 2002 2003 2005 2006 2007 2009 2010 2011 2013 2014 2015 2017 2018 2019]
leapyears= [1972 1976 1980 1984 1988 1992 1996 2000 2004 2008 2012 2016 2020]
for t = 19820325:20201231
             %try
        url = sprintf('somewebsite',a,b,c);
        target = 'Neerslag:' %Make sure that the webpage is in the right language form. Target should then greatly resemble the text. Wrong values might be there due to faults in the script.
        data = urlfilter(url,target) 
     if data == -1
        data = 0
     end
        BestStation(r,2) = data
        pause(1)
             % catch
               % warning('weberror')  
               % weberror = weberror + 1
             %end
        r = r + 1
        c = c + 1
        if c > 28 
            while (b == 2 && a == ismember(normalyears, normalyears(1:end)))
           b = b + 1
           c = 1
            end
        end
         if c > 29 
            while (b == 2 && a == ismember(leapyears, leapyears(1:end)))
           b = b + 1
           c = 1
            end
        end
        if c > 30
            while (b == ismember(thirtydays, thirtydays(1:end)))
           b = b + 1
           c = 1
            end
        end      
        if c > 31
            while (b == ismember(thirtyonedays, thirtyonedays(1:end)))
           b = b + 1
           c = 1 
            end
        end
        if b > 12
           a = a + 1
           b = 1
           c = 1
        end
end

I made a loop this way so I can scrape through multiple webpages dependant on the changing dates

Something goes wrong though when the code enters the if section of this loop

I tried multiple ways of changing things around like swapping if and while, but there's something not logical about it yet (which I can not see how).

I'm using ismember now, but that doesnt seem to give the loop the magic touch.

Thank you for giving attention.

[Jacob]

Solved

[Stephen23]

Avoid encoding dates as one decimal integer where the digits happen to correspond to the digits of the year, month, and day.

for t = 19820325:20201231 % <--- avoid doing this!

Rather than messing around with badly encoded dates you should use DATETIME objects, which would simplify your code.

[Jacob]

Thank you. I noticed.

[Siddharth Bhutiya]

As Stephen already mentioned above, your life would be a lot easier if you use datetime when working with dates and times. You can get rid of all the date handling code that you have in your above example and focus on your actual task. For example I see that you have explicit code to correctly handle increments for different months and leap years, this is all automatically handled by datetime.

>> d = datetime(2020,2,28) 

d = 

  datetime

   28-Feb-2020

>> d + 1 % Its a leap year so incrementing the date by 1 day will give you 29th Feb

ans = 

  datetime

   29-Feb-2020

>> d = datetime(2021,2,28)

d = 

  datetime

   28-Feb-2021

>> d + 1 % 2021 is not a leap year so incrementing by 1 day will give you 1st Mar

ans = 

  datetime

   01-Mar-2021

[Jacob]

Thanks. I thought it worked to supplement sprinft code for scraping through various pages.