<?php
// your code goes here
$timeDiff = abs($endTimeStamp - $startTimeStamp);
$numberDays = $timeDiff/86400; // 86400 seconds in one day
// and you might want to convert to integer
$numberDays = intval($numberDays);
echo $numberDays;
PD9waHAKCi8vIHlvdXIgY29kZSBnb2VzIGhlcmUKCiRzdGFydFRpbWVTdGFtcCA9IHN0cnRvdGltZSgiMjAxNi8wMS8wNiIpOwokZW5kVGltZVN0YW1wID0gc3RydG90aW1lKCIyMDE2LzAxLzA4Iik7CgokdGltZURpZmYgPSBhYnMoJGVuZFRpbWVTdGFtcCAtICRzdGFydFRpbWVTdGFtcCk7CgokbnVtYmVyRGF5cyA9ICR0aW1lRGlmZi84NjQwMDsgIC8vIDg2NDAwIHNlY29uZHMgaW4gb25lIGRheQoKLy8gYW5kIHlvdSBtaWdodCB3YW50IHRvIGNvbnZlcnQgdG8gaW50ZWdlcgokbnVtYmVyRGF5cyA9IGludHZhbCgkbnVtYmVyRGF5cyk7CgplY2hvICRudW1iZXJEYXlzOw==