How to section a date period monthly - php

Question

two dates 13-10-2017 and 13-02-2018. I want to separate this period in months like 13-10-2017 to 31-10-2-17, 01-11-2017 to 30-11-2017, 01-12-2017 to 31-12-2017, 01-01-2018 to 31-01-2018 and 01-02-2018 to 13-02-2018. What I did I can get the month names in the date period but not in the format I want.
Here is my code:
$start_date = new DateTime('13-10-2017');
$end_date = new DateTime('13-02-2018');
$date_interval = new DateInterval('P1M');
$date_period = new DatePeriod($start_date, $date_interval, $end_date);
# calculating number of days in the interval
$interval = $start_date->diff( $end_date );
$days = $interval->days;
# getting names of the months in the interval
$month_count = 0;
$month_names = array();
foreach ($date_period as $date) {
$month_names[] = $date->format('F');
$month_count++;
}
$month_name_string = implode(',', $month_names);
echo $start_date->format('d-m-Y').' to '.$end_date->format('d-m-Y'). ' is ' .$days.' days and month names are: '.$month_name_string;
The output I get :
13-10-2017 to 13-02-2018 is 123 days and month names are: October,November,December,January

Answer 1

You can, while iterating, do the following checks:
If the current month is in $start_date, use its day for the start date
If the current month is in $end_date, use its day for the last day
Else, use the 1 and maximum day of each month (using the t format character)
Also, you need to set the time to 00:00:01 in the final day in order to have it considered in the DateInterval:
<?php
$start_date = new DateTime('13-10-2017');
$end_date = new DateTime('13-02-2018');
$end_date->setTime(0, 0, 1); // important, to consider the last day!
$date_interval = new DateInterval('P1M');
$date_period = new DatePeriod($start_date, $date_interval, $end_date);
# calculating number of days in the interval
$interval = $start_date->diff( $end_date );
$days = $interval->days;
# getting names of the months in the interval
$dates = [];
foreach ($date_period as $date) {
$dateArr = [];
if ($date->format("Y-m") === $start_date->format("Y-m")) {
$dateArr["start"] = $start_date->format("d-m-Y");
}
else {
$dateArr["start"] = $date->format("01-m-Y");
}
if ($date->format("Y-m") === $end_date->format("Y-m")) {
$dateArr["end"] = $end_date->format("d-m-Y");
}
else {
$dateArr["end"] = $date->format("t-m-Y"); // last day of the month
}
$dates[] = $dateArr;
}
foreach ($dates as $date) {
echo $date["start"]." to ".$date["end"].PHP_EOL;
}
Demo

Answer 2

You can employ DateTime::modify function. E.g.:
$month_intervals = [];
foreach ($date_period as $date) {
$start = $date == $start_date ? $start_date : $date->modify('first day of this month');
$month_intervals[] = join([
$start->format('d-m-Y'),
$date->modify('last day of this month')->format('d-m-Y')
], ' to ');
}
$month_intervals[] = join([
(clone $end_date)->modify('first day of this month')->format('d-m-Y'),
$end_date->format('d-m-Y')
], ' to ');
echo implode(',', $month_intervals);