Incorrect date

[Luis]

I've adapted the following code so that it prints the date in
DD/MM/YYYY format. However it prints the incorrect date! If todays
date is 01/01/2003 it prints 03/01/2003 - 3 days out! What have I done
wrong?


<script language="Javascript">
aCalendar = new Date();
CalendarDay = aCalendar.getDay();
CalendarMonth = aCalendar.getMonth();
CalendarDate = aCalendar.getDate();
CalendarYear = aCalendar.getYear();

var monthname = new Array ("01", "02", "03", "04", "05", "06", "07",
"08", "09", "10", "11", "12" );
var dayname = new Array ("01", "02", "03", "04", "05", "06", "07",
"08", "09", "10", "11", "12", "13", "14", "15", "16", "17", "18",
"19", "20", "21", "22", "23", "24", "25", "26", "27", "28", "29",
"30", "31" );

if (CalendarDate < 10) MonthSize=("0" + CalendarMonth + "/");
else MonthSize=(CalendarDate + "/");
if (CalendarDate < 10) DaySize=("0" + CalendarDay + "/");
else DaySize=(CalendarDate + "/");
var TheDateIs = dayname[CalendarDay] + "/" + monthname[CalendarMonth]
+ "/" + CalendarYear
document.write("Todays date is: " + TheDateIs)

</script>


If I change

CalendarDay = aCalendar.getDay();

to:

CalendarDay = aCalendar.getDay()-3;

it displays the correct date. But isn't there a better solution?
I need the date in DD/MM/YYYY format, ie 01/01/2003

 

[Lasse Reichstein Nielsen]

I've adapted the following code so that it prints the date in
DD/MM/YYYY format. However it prints the incorrect date! If todays
date is 01/01/2003 it prints 03/01/2003 - 3 days out! What have I done
wrong?

A few problems:

CalendarDay = aCalendar.getDay();

You probably don't need getDay. It returns the number of the day in
the week, not the day in the month.

CalendarYear = aCalendar.getYear();

You might want to use getFullYear if it exists.

var dayname = new Array ("01", "02", "03", "04", "05", "06", "07",
"08", "09", "10", "11", "12", "13", "14", "15", "16", "17", "18",
"19", "20", "21", "22", "23", "24", "25", "26", "27", "28", "29",
"30", "31" );

with this definition, dayname[1]=="02".
The date object getDate returns the date, and your array is one off,
since it starts at index zero.

Notice that the getMonth method returns the month number minus one,
so January is month zero. Your month array works correctly.

if (CalendarDate < 10) MonthSize=("0" + CalendarMonth + "/");
else MonthSize=(CalendarDate + "/");

If the date is <10 you add a zero in front of the month, else not
in front of the date???

Later, you don't use MonthSize at all.

if (CalendarDate < 10) DaySize=("0" + CalendarDay + "/");
else DaySize=(CalendarDate + "/");

You use Day and Date interchangably. Today is the third, so Date is 3.
It is a Friday, so Day is 5.

Again, you don't use DaySize at all.

var TheDateIs = dayname[CalendarDay] + "/" + monthname[CalendarMonth]
+ "/" + CalendarYear

So this is where you look up the dayname (where you mean datename) by
the week day and one off.

Try this:
---
var aCalendar = new Date();
var theDate = aCalendar.getDate();
if (theDate < 10) {theDate = "0"+theDate;}
var theMonth = aCalendar.getMonth();
if (theMonth<10) {theMonth = "0"+theMonth;}
var theYear;
if (aCalendar.getFullYear) {
theYear = aCalendar.getFullYear(); // use getFullYear if it exists
} else {
theYear = aCalendar.getYear(); // use getYear, add 1900 depending on browser
if (theYear<1900) {
theYear += 1900;
}
}
var TheDateIs = theDate+"/"+theMonth+"/"+theYear;
---

You should seriously consider another format for the date. Neither
dd/mm/yyyy nor mm/dd/yyyy are universally understandable. In an
international setting like the internet, yyyy/mm/dd is much safer.

/L

 

[Dr John Stockton]

JRS: In article <[email protected]>, seen in

Typing. That's 2 days out; your code gives 04/01/2003.

When posting code, do not let your news-reader line-wrap it.

Read the FAQ.

var aCalendar = new Date();
var theDate = aCalendar.getDate();
if (theDate < 10) {theDate = "0"+theDate;}
var theMonth = aCalendar.getMonth() // +1 ?
if (theMonth<10) {theMonth = "0"+theMonth;}

var theYear;
if (aCalendar.getFullYear) {
theYear = aCalendar.getFullYear(); // use getFullYear if it exists
} else {
theYear = aCalendar.getYear(); // use getYear, add 1900 depending on browser
if (theYear<1900) {
theYear += 1900;
}

I don't see the point of all that. If one assumes that getFullYear
might not be implemented (good) but getYear will be (seems safe), and so
codes for getYear, why bother with getFullYear at all? It seems too
far-sighted.

theYear = 1900 + aCalendar.getYear()%1900 // should do, < 3800 AD

 

[Luis]

When posting code, do not let your news-reader line-wrap it.

Posted via Google Groups so I can't control the wrapping(?)

---

Thanks for the script advice everyone...

For the sake of having a complete thread for the Google archives, I'll
probably go with a variation of the following code as the solution to
the question I posted:

dim TodaysDate, TodaysMonth, TodaysDay

TodaysDate = dateadd("n",application("localoffset"),now())

if len(month(TodaysDate)) = 1 then
TodaysMonth = "0"& month(TodaysDate)
else
TodaysMonth = month(TodaysDate)
end if

if len(day(TodaysDate)) = 1 then
TodaysDay = "0"& day(TodaysDate)
else
TodaysDay = day(TodaysDate)
end if

TodaysDate = year(TodaysDate)& "/"& TodaysMonth& "/"& TodaysDay

This should print: 2003/10/06

 

[Dr John Stockton]

JRS: In article <[email protected]>, seen in

Posted via Google Groups so I can't control the wrapping(?)

Non sequitur. You need to put newlines in your code sufficiently often.

Exercise for regulars - how narrow can ECMA-compatible
javascript be written?

---

Thanks for the script advice everyone...

For the sake of having a complete thread for the Google archives, I'll
probably go with a variation of the following code as the solution to
the question I posted:

dim TodaysDate, TodaysMonth, TodaysDay

TodaysDate = dateadd("n",application("localoffset"),now())

if len(month(TodaysDate)) = 1 then
TodaysMonth = "0"& month(TodaysDate)
else
TodaysMonth = month(TodaysDate)
end if

if len(day(TodaysDate)) = 1 then
TodaysDay = "0"& day(TodaysDate)
else
TodaysDay = day(TodaysDate)
end if

TodaysDate = year(TodaysDate)& "/"& TodaysMonth& "/"& TodaysDay

This should print: 2003/10/06

Your if statements could be replaced by use of something like

function LZ(x) {return(x<0||x>9?"":"0")+x}


Your code looks like VBS. My test process dislikes the "dateadd" line;
replacing the function with 3, the result is 1900/01/02, which is proper.


For a change :

with (new Date()) TheDate =
String((getFullYear()*100+getMonth()+1)*100+getDate()).
replace(/(\d\d)(\d\d)$/, '/$1/$2')

with (new Date()) { setMinutes(getMinutes()+LocalOffset)
TheDate =
String((getFullYear()*100+getMonth()+1)*100+getDate()).
replace(/(\d\d)(\d\d)$/, '/$1/$2') }

However, javascript has no direct access to LocalOffset;

with (new Date()) TheDate =
String((getUTCFullYear()*100+getUTCMonth()+1)*100+getUTCDate()).
replace(/(\d\d)(\d\d)$/, '/$1/$2')

 

[Lasse Reichstein Nielsen]

Exercise for regulars - how narrow can ECMA-compatible
javascript be written?

Length of the longest keyword is 10 characters ("instanceof"),
followed by "continue", "function" at 8 characters. I would say ten
characters wide is sufficient. The narrowest *usable* would probably
be four characters, if you don't use the longer keywords. Then
you can create strings containing arbitrary code, and evaluate
it with "eval".

If you use "continue" with a label, I am not sure it can broken into
separate lines. That is "break L" and "continue L" cannot be made
shorter. That still means a ten-character minimum.

For just accessing properties, four characters are sufficient.
You will have to use square bracket notation and cut strings into
small parts to access long property names.

E.g.,
document.getElementById("foo").style.visiblity="visible";
can be coded in four-character lines. First we need an object to start
from in order to use square bracket notation, so we write it as

var s=self;
s["document"]["getElementById"]("foo")["style"]["visibility"]="visible";

(Luckily, "self" is shorter than "window")

We then split the strings into lines of at most four characters,
making sure to end each line with an character that prevents semicolon
insertion:

0123 0123 0123 0123 0123 0123 0123 0123 0123 0123 0123 0123
var s= self ; s[ "d"+ "o"+ "c"+ "u"+ "m"+ "e"+ "n"+
"t" ][ "g"+ "e"+ "t"+ "E"+ "l"+ "e"+ "m"+ "e"+ "n"+ "t"+
"B"+ "y"+ "I"+ "d" ]( "f"+ "o"+ "o" )[ "s"+ "t"+ "y"+
"l"+ "e" ][ "v"+ "i"+ "s"+ "i"+ "b"+ "i"+ "l"+ "i"+ "t"+
"y" ]= "v"+ "i"+ "s"+ "i"+ "b"+ "l"+ "e";

Identifiers-like keywords of four characters ("this","true","null")
can be renamed as
var
x=
this
;
or
var
t=
true
;
The five-character keyword "false" can then be renamed using "!t".
var
f=
!t;


The above lines of four characters on the form "c"+ makes it look like
four is a minimum for composing strings. It isn't. With two extra
variable, you can compose strings with only three characters per line.

var
c;
var
t=
"b"
;
c=
"a"
;
t+=
c;
c=
"z"
;
t+=
c;
f(
t);

Still, you need four characters in order to call "eval" (because
four characters is the shortest possible needed to access the
global object so you can use "eval").


Enough
for
now.
/L