Finding First day of week via php [duplicate]

Answer 1

Here's a function for the first and last day of the week:

function week_start_date($wk_num, $yr, $first = 1, $format = 'F d, Y') 
{ 
    $wk_ts  = strtotime('+' . $wk_num . ' weeks', strtotime($yr . '0101')); 
    $mon_ts = strtotime('-' . date('w', $wk_ts) + $first . ' days', $wk_ts); 
    return date($format, $mon_ts); 
} 

$sStartDate = week_start_date($week_number, $year); 
$sEndDate   = date('F d, Y', strtotime('+6 days', strtotime($sStartDate))); 

It can probably be adapted to do month as well, but I wanted to get my answer in! :)

Answer 2

strtotime is quite powerful with relative time formats:

strtotime('monday this week');
strtotime('sunday this week');
strtotime('monday last week');
strtotime('sunday last week');

(this only works with PHP 5.3+)

strtotime('first day of this month');
strtotime('last day of this month');
strtotime('first day of last month');
strtotime('last day of last month');

In order to get the first and last date of a month in PHP < 5.3, you can use a combination of mktime and date (date('t') gives the number of days of the month):

mktime(0,0,0,null, 1); // gives first day of current month
mktime(0,0,0,null, date('t')); // gives last day of current month

$lastMonth = strtotime('last month');
mktime(0,0,0,date('n', $lastMonth), 1); // gives first day of last month
mktime(0,0,0,date('n', $lastMonth), date('t', $lastMonth); // gives last day of last month

If you just want to get a string for presentation, then you don't need mktime:

date('Y-m-1'); // first day current month
date('Y-m-t'); // last day current month
date('Y-m-1', strtotime('last month')); // first day last month
date('Y-m-t', strtotime('last month')); // last day last month