datetime: split a month 10-day periods - php

Question

I send a earlier date and it returns me the periods between the earlier date and today cut by tens of days.
Example with 14/01/2016
I need the result to be exactly as below:
11 Jan 2016 to 20 Jan 2016
21 Jan 2016 to 31 Jan 2016
01 Feb 2016 to 10 Feb 2016
11 Feb 2016 to 20 Feb 2016
21 Feb 2016 to 29 Feb 2016
01 Mar 2016 to 10 Mar 2016
11 Mar 2016 to 20 Mar 2016
21 Mar 2016 to 31 Mar 2016
01 Apr 2016 to 10 Apr 2016
11 Apr 2016 to 20 Apr 2016
Here my code:
function date_interval($startTime = false){
if( ! $startTime){
return array();
} else {
if(date('d',$startTime) < 10){
$actual = mktime(0, 0, 0, date('m',$startTime), 1, date('Y',$startTime));
} elseif(date('d',$startTime) < 20){
$actual = mktime(0, 0, 0, date('m',$startTime), 10, date('Y',$startTime));
} else {
$actual = mktime(0, 0, 0, date('m',$startTime), 20, date('Y',$startTime));
}
if(date('d',time()) < 10) {
$target = mktime(0, 0, 0, date('m',time()), 10, date('Y',time()));
} elseif(date('d',time()) < 20) {
$target = mktime(0, 0, 0, date('m',time()), 20, date('Y',time()));
} else {
$target = mktime(0, 0, 0, date('m',time())+1, 1, date('Y',time()));
}
$current = $actual;
$last = $actual;
while($current < $target) {
if(date('d',$current) < 10){
$current = mktime(0, 0, 0, date('m',$current), 10, date('Y',$current));
} elseif(date('d',$current) < 20){
$current = mktime(0, 0, 0, date('m',$current), 20, date('Y',$current));
} else {
$current = mktime(0, 0, 0, date('m',$current)+1, 1, date('Y',$current));
}
$dateTime[date("Y-m-d", $last) .'~'. date("Y-m-d", $current)] = date('d M Y',$last) . ' - ' . date('d M Y',$current));
$last = $current;
}
}
return $dateTime;
}

Answer 1

Datetime is the darling class from php that solves this type of problem nicely.
Here you feed the startdate to the function as DATETIME object and the function throws back a stack of list tags.
In the loop startDay is beeing modyfied first by adding 10 days to make the jump and then by one to avoid the overlap.
If you want a final line with the (less then ten days) time period from last startDay till today you can add something like:
$return .= '<li>From '.$startDay->format('d M Y').' to '.$today->format('d M Y').'</li>';
after the loop
function date_interval(DATETIME $startDay = NULL)
{
if( NULL == $startDay){
return array(); }
$return = '';
$today = new DATETIME('now');
while( $today->diff( $startDay )->format('%a%') > 10 )
{
$return .= '<li>From '.$startDay->format('d M Y').' to ';
$startDay->modify('+10 days');
$return .= $startDay->format('d M Y').'</li>
';
$startDay->modify('+1 day');
}
return $return;
}
I altered the above more general solution to do exactly what you describe:
<?php
function date_interval(DATETIME $startDay = NULL)
{
if( NULL == $startDay){
return array(); }
$return = '';
$today = new DATETIME('now');
$startMonth = new DateTime('first day of '.$startDay->format('M Y') );
$firstRun = TRUE;
while( $today > $startDay )
{
$return .= '<li>From '.$startDay->format('d M Y').' to ';
if( $firstRun == TRUE ){
if( (int)$startDay->format('d') > 10 )
$startMonth->modify('+10 days');
if( (int)$startDay->format('d') > 20 )
$startMonth->modify('+10 days');
$startDay = $startMonth;
$firstRun = FALSE;
}
$lastOfMonth = new DateTime('last day of '.$startDay->format('M Y') );
if( $lastOfMonth->diff( $startDay )->format('%a%') > 10 )
$startDay->modify('+9 days');
else
$startDay = $lastOfMonth;
$return .= $startDay->format('d M Y').'</li>
';
$startDay->modify('+1 day');
}
return $return;
}
echo date_interval( date_create_from_format('Y-m-d','2016-01-21') )."\n";
?>

Answer 2

See this function using DateTime:
function date_interval( $start = Null )
{
if( !$start ) return array();
$cur = new DateTime( sprintf( '%s-%02d', $start->format('Y-m'), [1,11,21,21][ floor(($start->format('j')-1)/10) ] ) );
$end = new DateTime();
$retval = [];
while( $cur <= $end )
{
$key = $cur->format( 'Y-m-d~' );
$val = $cur->format( 'd M Y - ' );
if( $cur->format( 'j' ) > 20 ) $cur->modify( 'last day of this month' );
else $cur->modify( '+ 9 days' );
$retval[ $key.$cur->format( 'Y-m-d' ) ] = $val.$cur->format( 'd M Y' );
$cur->modify( '+ 1 days' );
}
return $retval;
}
Calling it in this way:
$startDate = '14/01/2016';
$array = date_interval( DateTime::createFromFormat( 'd/m/Y', $startDate ) );
print_r( $array );
According with your keys/values schema, the resulting array is:
Array
(
[2016-01-11~2016-01-20] => 11 Jan 2016 - 20 Jan 2016
[2016-01-21~2016-01-31] => 21 Jan 2016 - 31 Jan 2016
[2016-02-01~2016-02-10] => 01 Feb 2016 - 10 Feb 2016
[2016-02-11~2016-02-20] => 11 Feb 2016 - 20 Feb 2016
[2016-02-21~2016-02-29] => 21 Feb 2016 - 29 Feb 2016
[2016-03-01~2016-03-10] => 01 Mar 2016 - 10 Mar 2016
[2016-03-11~2016-03-20] => 11 Mar 2016 - 20 Mar 2016
[2016-03-21~2016-03-31] => 21 Mar 2016 - 31 Mar 2016
[2016-04-01~2016-04-10] => 01 Apr 2016 - 10 Apr 2016
[2016-04-11~2016-04-20] => 11 Apr 2016 - 20 Apr 2016
[2016-04-21~2016-04-30] => 21 Apr 2016 - 30 Apr 2016
)
We operate only on one date ($cur), initially created from passed argument; we set the day of month using array [1,11,21,21] and selecting key by the rounded down division by 10 of original day (in your example, (14-1)/10 = 1.3, rounded as 1, that is 11 in [1,11,21,21] array). This is a quick way to resolve the 31th day exception.
Then we perform a loop until $cur date is greater than today date: we create starting part of key and value, we modify $cur adding it nine days or selecting last month's day, we create complete key and value of returned array. At the end of each loop, we increment $cur by 1 day.