get average of given dates in php - php

Question

I try to get an average of given dates but I failed when dates are from two different years. I need something like this
given dates:
2017-06-1
2017-06-3
2017-06-4
2017-06-3
2017-06-5
output : 2017-06-4
this is my code:
$total = 0;
foreach ($dates as $date) {
$total+= date('z', strtotime($date))+1;
}
$avg_day = $total/sizeof($dates);
$date = DateTime::createFromFormat('z Y', $avg_day . ' ' . date("Y"));
but my code is not working for
given dates:
2016-12-29
2016-12-31
2017-01-1
2017-01-5
2017-01-3

Answer 1

You can work with timestamp of the date and use avg() method of the Illuminate\Support\Collection
$dates = [
'2016-12-29', '2016-12-31', '2017-01-1', '2017-01-5', '2017-01-3'
];
$dateCollection = collect();
foreach($dates as $date){
$dateCollection->push((new \DateTime($date))->getTimestamp());
}
$averageTimestamp = $dateCollection->avg(); //timestamp value
$averageDate = date('Y-m-d', $average);
Or using Carbon package:
$dateCollection->push(Carbon::parse($date)->timestamp);
...
$averageDate = Carbon::createFromTimestamp($average)->toDateString();

Answer 2

Your code is not working for your base dates. The correct output for
2017-06-1 2017-06-3 2017-06-4 2017-06-3 2017-06-5
is
2017-06-03
According to OpenOffice calc, and overall logic (a date is represented by epoch number)
Check out this script
$dates = ['2017-06-1 ', '2017-06-3', '2017-06-4', '2017-06-3', '2017-06-5'];
$dates = array_map('strtotime', $dates);
$average = date('Y-m-d', array_sum($dates) / count($dates)); // 2017-06-03 (1496490480)
echo $average;
Keep simple tasks simple

Answer 3

I think you have problem with averaging year. So, You can do this to get average.
Just an algorithm:
Find smallest date among your dates at first as $smallest
Initiate a variable $total = 0;
Add difference of each date in days with smallest date.
Find average from total.
Add this total to smallest date.
Here, You have smallest as $smallest = '2016-12-29'
$total = 0;
$dates = ['2016-12-29', '2016-12-31', '2017-01-1', '2017-01-5', '2017-01-3'];
$smallest = min($dates);
$smallest = Carbon::parse($smallest);
foreach($dates as $date){
$d = Carbon::parse($date);
$total = $total+$smallest->diffInDays($d);
}
$average_day = $total/sizeof($dates);
$average_date = $smallest->addDays($average_day);
Hope, This might help you.