Posted by john.d.mann@sbcglobal.net on 01/15/06 15:11

Oli Filth wrote:
> john.d.mann@sbcglobal.net said the following on 13/01/2006 18:34:
>
>> VS wrote:
>>
>>> john.d.mann@sbcglobal.net wrote:
>>>
>>>> lwoods wrote:
>>>>
>>>>> I want to calculate and display the 'mm/dd/yyyy' that is 10 years
>>>>> earlier than today.
>>>>>
>>>> // configuration
>>>> $date = '01/01/2006';
>>>> $offset = '-10';
>>>> $date_glue = '/';
>>>>
>>>> // implementation
>>>> $temp = explode($date_glue, $date);
>>>> $temp[2] = $temp[2] + $offset;
>>>> $date = implode ($date_glue, $date);
>>>> echo $date;
>>>
>>>
>>>
>>>
>>> That technique only works for some date calculations.
>>>
>>> Try to take off 10 days during the first 10 days of the month or 10
>>> months between Jan and October and you'll get strange results.
>>>
>>
>> Well, sure, but he was only asking about the year hehe. For the day
>> or month, a more advanced version would be required.
>>
>
> How about 29/02/2004?
>
>

hehe - Well, the title of the thread says mm/dd/yyyy. So, again, i was
just going by the data given by the thread starter. You can always
adapt your code to handle the format of dd/mm/yyyy. Something like this...

// configuration
$date = '01/01/2006';
$offset = '-10';
$date_glue = '/';

// change if your month is in a different position, such as dd/mm/yy
$month_location = '1';
$day_location = '2';

// implementation
$temp = explode($date_glue, $date);
if $temp[$day_location - 1] < 11
{
$eat_previous_month_by_this = 10 - $temp[$day_location - 1];
switch ($temp[$month_location - 1]) {
case 1:
$temp[$month_location - 1] = 12;
$temp[$day_location - 1] = 31 - $eat_previous_month_by_this;
break;
case 2:
$temp[$month_location - 1]--;
$temp[$day_location - 1] = 31 - $eat_previous_month_by_this;
break;
case 3:
$temp[$month_location - 1]--;
// check for leap year here. is year divisible by four? if so, then
use 29, if not then use 28. a simple if statement should suffice.
$temp[$day_location - 1] = 28 - $eat_previous_month_by_this;
break;
case 4:
$temp[$month_location - 1]--;
$temp[$day_location - 1] = 31 - $eat_previous_month_by_this;
break;
case 5:
$temp[$month_location - 1]--;
$temp[$day_location - 1] = 30 - $eat_previous_month_by_this;
break;
case 6:
$temp[$month_location - 1]--;
$temp[$day_location - 1] = 31 - $eat_previous_month_by_this;
break;
case 7:
$temp[$month_location - 1]--;
$temp[$day_location - 1] = 30 - $eat_previous_month_by_this;
break;
case 8:
$temp[$month_location - 1]--;
$temp[$day_location - 1] = 31 - $eat_previous_month_by_this;
break;
case 9:
$temp[$month_location - 1]--;
$temp[$day_location - 1] = 31 - $eat_previous_month_by_this;
break;
case 10:
$temp[$month_location - 1]--;
$temp[$day_location - 1] = 30 - $eat_previous_month_by_this;
break;
case 11:
$temp[$month_location - 1]--;
$temp[$day_location - 1] = 31 - $eat_previous_month_by_this;
break;
case 12:
$temp[$month_location - 1]--;
$temp[$day_location - 1] = 30 - $eat_previous_month_by_this;
break;
}
}
$temp[$day_location - 1] = $temp[$day_location - 1] + $offset;
$date = implode ($date_glue, $date);
echo $date;

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