php calculate date difference

1//get Date diff as intervals 
2$d1 = new DateTime("2018-01-10 00:00:00");
3$d2 = new DateTime("2019-05-18 01:23:45");
4$interval = $d1->diff($d2);
5$diffInSeconds = $interval->s; //45
6$diffInMinutes = $interval->i; //23
7$diffInHours   = $interval->h; //8
8$diffInDays    = $interval->d; //21
9$diffInMonths  = $interval->m; //4
10$diffInYears   = $interval->y; //1
11
12//or get Date difference as total difference
13$d1 = strtotime("2018-01-10 00:00:00");
14$d2 = strtotime("2019-05-18 01:23:45");
15$totalSecondsDiff = abs($d1-$d2); //42600225
16$totalMinutesDiff = $totalSecondsDiff/60; //710003.75
17$totalHoursDiff   = $totalSecondsDiff/60/60;//11833.39
18$totalDaysDiff    = $totalSecondsDiff/60/60/24; //493.05
19$totalMonthsDiff  = $totalSecondsDiff/60/60/24/30; //16.43
20$totalYearsDiff   = $totalSecondsDiff/60/60/24/365; //1.35

1$firstDate = "2019-01-01";
2$secondDate = "2020-03-04";
3
4$dateDifference = abs(strtotime($secondDate) - strtotime($firstDate));
5
6$years  = floor($dateDifference / (365 * 60 * 60 * 24));
7$months = floor(($dateDifference - $years * 365 * 60 * 60 * 24) / (30 * 60 * 60 * 24));
8$days   = floor(($dateDifference - $years * 365 * 60 * 60 * 24 - $months * 30 * 60 * 60 *24) / (60 * 60 * 24));
9
10echo $years." year,  ".$months." months and ".$days." days";
11
12//output: 1 year, 2 months and 3 days