1 | Ben Donoghue
April 21, 2008 at 9:21 am

Hey,

Just had a nosey at your function and cool, it works great…

…except when you try something like [code]echo get_firstmonday(6,2008);[/code]

This gives 2008-06-09 00:00:00 which is the second Monday. This is because date(’w') gives the days of the week STARTING ON SUNDAY as 0. Therefore, any month starting on a Sunday will not work correctly. For myself I’ve made a small change if you’re interested:

[code]
function get_firstmonday($month,$year){

$num = date("w",mktime(0,0,0,$month,1,$year));
if($num==1)
return date("Y-M-d H:i:s",mktime(0,0,0,$month,1,$year));
elseif($num>1)
return date("Y-M-d H:i:s",mktime(0,0,0,$month,1,$year)+(86400*(8-$num)));
else
return date("Y-M-d H:i:s",mktime(0,0,0,$month,1,$year)+(86400*(1-$num)));

}
[/code]

I’ve not tried it but you may be able to use date(’N') in your original function to get Sunday as 7 instead of 0.

Cheers for it!

3 | karlamarie
May 16, 2008 at 6:26 am

How about getting the second, third and fourth Mondays?
Can you please help me?

5 | Ranjita
July 15, 2008 at 9:12 am

Hi

i have a posted date and day number (sunday=0, monday=1 etc),
i want a function that calculate next immediate date depending on the day number passed to the function.

I have a function which calculate the first, last,second ,forth day of current month… but i this function wont work if i give the posted date .

$answer=strftime(”%d-%m-%Y”, get_first_day($daym, $cur_month, $cur_year,$onthe));

function get_first_day($day_number, $month, $year, $onthe)
{
$month = ($month === false) ? strftime(”%m”): $month;
$year = ($year === false) ? strftime(”%Y”): $year;

$first_day = 1 + ((7+$day_number – strftime(”%w”, mktime(0,0,0,$month, 1, $year)))%7);
if($onthe ==’1′)
{
$set_value =”";
}
elseif($onthe ==’2′)
{
$set_value =”7″;
}
elseif($onthe ==’3′)
{
$set_value =”14″;
}
elseif($onthe ==’4′)
{
$set_value =”21″;
}
elseif($onthe ==’5′)
{
//if current day of week is sunday, than only we manupulate this otherwise it will take $set_value =”21″;
$set_value =”21″;
}
return mktime(0,0,0,$month, $first_day+$set_value, $year);
}

7 | Joe Dundas
February 21, 2009 at 4:26 pm

I just realized that I didn’t post the entire code. Sorry, here is the entire function.

function get_Xth_DOW($DOW,$X,$M,$Y) {
$numDays = date(’t',mktime(0,0,0,$M,1,$Y));
$add = 7*($X – 1);
$firstDOW = date(’w',mktime(0,0,0,$M,1,$Y));
$diff = $firstDOW – $DOW;
$d = 1;
if($diff > 0) { $d += (7 – $diff); }
else if ($diff $numDays) { $d -= 7; }
return $d;
}

9 | dane514
March 8, 2009 at 6:07 pm

@joe dundas

Your code was a bit flawed, with some calculations totally overlooked. For one, the missing comparison operator that kook pointed out. Two, you declared and assigned $add but never used it anywhere. It should have been used in the comparisons at the end of the function where the numeral 7 was written. Three, if the elseif statement was true, the re-assigned variable of $d (in your case) would not have been assigned a meaningful result without further manipulation.

Nevertheless, I read the intended meaning of your code, and took it upon myself to correct it for all those unsure of the required modifications, as your function is still pretty handy.

The code below is the corrected version of joe’s function, for anyone that needs this functionality but couldn’t get the desired results.

function get_xth_dow($dow, $occurence, $m, $y)
{
$numdays = date(’t', mktime(0, 0, 0, $m, 1, $y));
$add = 7 * ($occurence – 1);
$firstdow = date(’w',mktime(0, 0, 0, $m, 1, $y));
$diff = $firstdow – $dow;

$day_of_month = 1;
if($diff > 0)
{
$day_of_month += ($add – $diff);
}
elseif ($diff < $numdays)
{
$day_of_month -= ($diff – $add);
}
return $day_of_month;
}

13 | Joe Dundas
March 20, 2009 at 3:33 am

Frick. I have to make it printable in HTML. Lets see if this comes out right.

function get_Xth_DOW($DOW,$X,$M,$Y) {
$numDays = date(’t',mktime(0,0,0,$M,1,$Y));
$add = 7*($X – 1);
$firstDOW = date(’w',mktime(0,0,0,$M,1,$Y));
$diff = $firstDOW – $DOW;
$d = 1;
if($diff > 0) { $d += (7 – $diff); }
else if ($diff < 0) { $d += -1*$diff; }
$d = $d + $add;
while($d > $numDays) { $d -= 7; }
return $d;
}