Determine next Friday's date?

[CK]

Hi All,
Looking for a simple function to return the date for the follwing Friday. I
send out emails from time to time and I would like a function that
dynamically returns the date for the follwing Friday. So no matter what day
I send it, it will dynamically calculate Friday's date. Also if I am sending
it on a Friday, I would like to return the current date, Saturday and later
will return next Friday's date. Thanks for any advice.

Kind Regards,
CK

[CK]

I wrote one that works.

function nextFriday()
{
var d = new Date();

switch (d.getDay())
{
case 0: d.setDate(d.get Date() + 5);
break;

case 1: d.setDate(d.get Date() + 4);
break;

case 2: d.setDate(d.get Date() + 3);
break;

case 3: d.setDate(d.get Date() + 2);
break;

case 4: d.setDate(d.get Date() + 1);
break;

case 6: d.setDate(d.get Date() + 6);
break;
}

return d;

}

"CK" <c_**********@h otmail.com> wrote in message
news:9x******** **********@news svr21.news.prod igy.com...

Hi All,
Looking for a simple function to return the date for the follwing Friday.
I send out emails from time to time and I would like a function that
dynamically returns the date for the follwing Friday. So no matter what
day I send it, it will dynamically calculate Friday's date. Also if I am
sending it on a Friday, I would like to return the current date, Saturday
and later will return next Friday's date. Thanks for any advice.

Kind Regards,
CK

[Jonas Raoni]

CK wrote:

I send it, it will dynamically calculate Friday's date. Also if I am sending
it on a Friday, I would like to return the current date, Saturday and later
will return next Friday's date. Thanks for any advice.

function nextDay(day){
var d = new Date;
(day = (Math.abs(+day || 0) % 7) - d.getDay()) < 0 && (day += 7);
return day && d.setDate(d.get Date() + day), d;
};

The day parameter ranges from 0 to 6.
--
Jonas Raoni Soares Silva
http://www.jsfromhell.com

[RobG]

Lee wrote:

CK said:

Hi All,
Looking for a simple function to return the date for the follwing Friday. I
send out emails from time to time and I would like a function that
dynamically returns the date for the follwing Friday. So no matter what day
I send it, it will dynamically calculate Friday's date. Also if I am sending
it on a Friday, I would like to return the current date, Saturday and later
will return next Friday's date. Thanks for any advice.

var d=new Date();
d.setDate(d.get Date()+(12-d.getDay())%7);

d is now the current date if it is Friday or the date of the next Friday.

Aw, what the heck, here's another based on a for loop:

for (var x=new Date(); x.getDay()!=5; x.setDate(x.get Date()+1)){}
alert('Next Friday is ... ' + x.getDate());


--
Rob

[Dr John Stockton]

JRS: In article <9x************ ******@newssvr2 1.news.prodigy. com>,
dated Thu, 23 Feb 2006 18:53:57 remote, seen in
news:comp.lang. javascript, CK <c_**********@h otmail.com> posted :

Looking for a simple function to return the date for the follwing Friday. I
send out emails from time to time and I would like a function that
dynamically returns the date for the follwing Friday. So no matter what day
I send it, it will dynamically calculate Friday's date. Also if I am sending
it on a Friday, I would like to return the current date, Saturday and later
will return next Friday's date. Thanks for any advice.

Before posting to a newsgroup, one should seek and read the newsgroup
FAQ; see below.

I presume that you want to use local civil dates.

Ignore any "solutions" that you may be offered that contain, implicitly
or explicitly, the number 86400000. Any such is necessarily either
incompletely reliable or unduly long.

BTW, since yours appears to be a non-Web application it may be that you
should really have asked in one of the Microsoft scripting groups, where
most questions are about local execution under WSH.

The answer is given via the FAQ, in js-date7.htm#NPXD ; with D = new
Date() :-

// X = 0..6 = Sun..Sat

D.setDate( D.getDate() + (7+X-D.getDay())%7 )

Note : Many people are sometimes still active after midnight. If you
may be such, it could be wise to subtract say four hours before
executing the above. Your personal "day" will then run from 04:00 to
28:00, local.

--
© John Stockton, Surrey, UK. ?@merlyn.demon. co.uk Turnpike v4.00 IE 4 ©
<URL:http://www.jibbering.c om/faq/> JL/RC: FAQ of news:comp.lang. javascript
<URL:http://www.merlyn.demo n.co.uk/js-index.htm> jscr maths, dates, sources.
<URL:http://www.merlyn.demo n.co.uk/> TP/BP/Delphi/jscr/&c, FAQ items, links.

[RobG]

RobG wrote:
[...]

Aw, what the heck, here's another based on a for loop:

for (var x=new Date(); x.getDay()!=5; x.setDate(x.get Date()+1)){}
alert('Next Friday is ... ' + x.getDate());

And if the need is for *next* Friday's date if today is Friday, then:

for (var x=new Date(); x.setDate(x.get Date()+1) && x.getDay()!=5; ){}
alert('Next Friday\'s date is: ' + x.getDate());
--
Rob

[Thomas 'PointedEars' Lahn]

CK wrote:

I wrote one that works.

function nextFriday()
{
var d = new Date();

switch (d.getDay())
{
case 0: d.setDate(d.get Date() + 5);
break;

case 1: d.setDate(d.get Date() + 4);
break;

case 2: d.setDate(d.get Date() + 3);
break;

case 3: d.setDate(d.get Date() + 2);
break;

case 4: d.setDate(d.get Date() + 1);
break;

case 6: d.setDate(d.get Date() + 6);
break;
}

return d;

}
Date.prototype. getNextWkDay = function(iWkDay )
{
if (typeof iWkDay == "undefined"
|| typeof iWkDay != "number")
{
// Monday is the default
iWkDay = 1;
}

iWkday = Math.floor(iWkD ay);

var x = iWkDay - this.getDay(), d = this;
if (x != 0)
{
var iDate = this.getDate();

d = new Date(
this.getFullYea r(),
this.getMonth() ,
iDate,
this.getHours() ,
this.getMinutes (),
this.getSeconds (),
this.getMillise conds());

if (x < 0)
{
x += 7;
}

d.setDate(iDate + x);
}

return d;
};

// get next Friday's date
var dNextFriday = new Date().getNextW kDay(5);
[Top post]

Don't do that again. <URL:http://jibbering.com/faq/>
PointedEars

[Thomas 'PointedEars' Lahn]

Thomas 'PointedEars' Lahn wrote:

Date.prototype. getNextWkDay = function(iWkDay )
{
if (typeof iWkDay == "undefined"
|| typeof iWkDay != "number")
{
// Monday is the default
iWkDay = 1;
}

iWkday = Math.floor(iWkD ay);

var x = iWkDay - this.getDay(), d = this;
if (x != 0)
{
var iDate = this.getDate();

d = new Date(
this.getFullYea r(),
this.getMonth() ,
iDate,
this.getHours() ,
this.getMinutes (),
this.getSeconds (),
this.getMillise conds());

if (x < 0)
{
x += 7;
}

d.setDate(iDate + x);
}

return d;
};

// get next Friday's date
var dNextFriday = new Date().getNextW kDay(5);

Date.prototype. getNextWkDay = function(iWkDay )
{
if (typeof iWkDay != "number" || iWkDay < 0)
{
// next Monday is the default
iWkDay = 1;
}
else
{
iWkday = Math.floor(iWkD ay) % 7;
}

var x = (iWkDay - this.getDay() + 7) % 7, d = this;
if (x != 0)
{
var iDate = this.getDate();

d = new Date(
this.getFullYea r(),
this.getMonth() ,
iDate,
this.getHours() ,
this.getMinutes (),
this.getSeconds (),
this.getMillise conds());

d.setDate(iDate + x);
}

return d;
};

// get next Friday's date
var dNextFriday = new Date().getNextW kDay(5);
PointedEars

[Thomas 'PointedEars' Lahn]

Thomas 'PointedEars' Lahn wrote:

Date.prototype. getNextWkDay = function(iWkDay )
{
if (typeof iWkDay == "undefined"
|| typeof iWkDay != "number")
{
// Monday is the default
iWkDay = 1;
}

iWkday = Math.floor(iWkD ay);

var x = iWkDay - this.getDay(), d = this;
if (x != 0)
{
var iDate = this.getDate();

d = new Date(
this.getFullYea r(),
this.getMonth() ,
iDate,
this.getHours() ,
this.getMinutes (),
this.getSeconds (),
this.getMillise conds());

if (x < 0)
{
x += 7;
}

d.setDate(iDate + x);
}

return d;
};

// get next Friday's date
var dNextFriday = new Date().getNextW kDay(5);

Date.prototype. getNextWkDay = function(iWkDay )
{
if (typeof iWkDay != "number" || iWkDay < 0)
{
// next Monday is the default
iWkDay = 1;
}

iWkday = Math.floor(iWkD ay) % 7;

var x = (iWkDay - this.getDay() + 7) % 7, d = this;
if (x != 0)
{
var iDate = this.getDate();

d = new Date(
this.getFullYea r(),
this.getMonth() ,
iDate,
this.getHours() ,
this.getMinutes (),
this.getSeconds (),
this.getMillise conds());

d.setDate(iDate + x);
}

return d;
};

// get next Friday's date
var dNextFriday = new Date().getNextW kDay(5);
PointedEars

[Dr John Stockton]

JRS: In article <rI************ *****@news.optu s.net.au>, dated Thu, 23
Feb 2006 23:39:03 remote, seen in news:comp.lang. javascript, RobG
<rg***@iinet.ne t.au> posted :

RobG wrote:
[...]

Aw, what the heck, here's another based on a for loop:

for (var x=new Date(); x.getDay()!=5; x.setDate(x.get Date()+1)){}
alert('Next Friday is ... ' + x.getDate());

And if the need is for *next* Friday's date if today is Friday, then:

for (var x=new Date(); x.setDate(x.get Date()+1) && x.getDay()!=5; ){}
alert('Next Friday\'s date is: ' + x.getDate());

Other than
* Determining the start and end of local Summer Time
according to the OS,
* Generating a list-type result,
is there any date/time calculation possible in javascript that *needs*
iteration?

--
© John Stockton, Surrey, UK. ?@merlyn.demon. co.uk Turnpike v4.00 IE 4 ©
<URL:http://www.jibbering.c om/faq/> JL/RC: FAQ of news:comp.lang. javascript
<URL:http://www.merlyn.demo n.co.uk/js-index.htm> jscr maths, dates, sources.
<URL:http://www.merlyn.demo n.co.uk/> TP/BP/Delphi/jscr/&c, FAQ items, links.