Simple logic error I can't figure out

Hey, I'm making a quick file for telling if a given date is in DST or not. It's telling me

Operands to the || and && operators must be convertible to logical scalar values.

I don't know why I'm getting this.

For input values, I'm using

month =

       7
       5
       2
day =

    12
    12
    12
Date2 = 

    '2014-07-12 19:06:10'
    '2014-05-12 19:06:20'
    '2014-02-12 19:06:30'

My code is as follows:

if (month > 3) && (month <11)
    DST=true;
elseif ((month < 3) || (month > 11))
    DST= false;
elseif (month == 3)
    if (day > 14)
        DST=true;
    elseif (day < 8)
        DST=false;
    else
        DOW = weekday(Date2,'yyyy-mm-dd');
        if (DOW == 1)
            DST=true;
        elseif (DOW > 1)
            today = str2double(Date2(9:10));
            if ((DOW == 2) && (today > 8))
                DST = true;
            elseif ((DOW == 3) && (today > 9))
                DST = true;
            elseif ((DOW == 4) && (today > 10))
                DST = true;
            elseif ((DOW == 5) && (today > 11))
                DST = true;
            elseif ((DOW == 6) && (today > 12))
                DST = true;
            elseif ((DOW == 7) && (today > 13))
                DST = true;
            else
                DST = false;
            end
        end
    end
elseif (month == 11)
    if (day > 7) 
        DST=false;
    else
        DOW = weekday(Date2,'mm/dd/yyyy');
        if (DOW == 1)
            DST=false;
        elseif (DOW > 1)
            today = str2double(Date2(4:5));
            if ((DOW == 2) && (today < 2))
                DST = true;
            elseif ((DOW == 3) && (today <3))
                DST = true;
            elseif ((DOW == 4) && (today <4))
                DST = true;
            elseif ((DOW == 5) && (today <5))
                DST = true;
            elseif ((DOW == 6) && (today <6))
                DST = true;
            elseif ((DOW == 7) && (today <7))
                DST = true;
            else
                DST = false;
            end
        end
    end
else
    DST = false;
end

Thanks!

Answer 1

[Star Strider]

Try single operators for ‘|’ and ‘&’.

[Mike Beacham]

Thank you! What's the difference?

[Star Strider]

My pleasure!

The double operators are ‘short circuit’ logical operators, and have special requirements. The single operators (for example or) perform simple logic operations.