Delays the next execution of the script by storing the next execution time in file and checking against it before continuing.

random_delay_next_run.php

<?php
// Random time delay before next execution.
// Stores the next time in a file.
// Time is read from this file and compared against current time.
// If time has passed, perform another random delay between 1-59 seconds before execution.

$timeFile = 'nexttime.txt';
// $timeFile = dirname(__FILE__).'/nexttime.txt';  // Use this line for when running from CRON.
$minDelayMins = 1;
$maxDelayMins = 5;

if(!file_exists($timeFile)){
  // Write new time to new file if file does not exist
  $newTimeDelay = writeNewTimeDelay();
  echo $timeFile.' does not exist. Created a new file with delay set to '.$newTimeDelay.' seconds from now.'.PHP_EOL;
  
}

$nextTime = file_get_contents($timeFile);

if(time()>=$nextTime){
  
  // Enough time has elpased, run the script
  echo 'TIME TO RUN...'.PHP_EOL;
  
  // Sleep for a randomly throughout the minute for randomization of execution time down to the second.
  $microsleep = rand(1000000,59000000); // 1 second <> 59 seconds
  echo 'PAUSING FOR '.($microsleep/1000000).' SECONDS'.PHP_EOL;
  usleep($microsleep);
  
  echo 'RUNNING!!!!!'.PHP_EOL;
  
    ///////////////////
   // Do Stuff Here //
  ///////////////////
  
  
  
  
  // Write new time to file
  $newTimeDelay = $newTimeDelay = writeNewTimeDelay();
  echo 'New delay set to '.$newTimeDelay.' seconds from now.'.PHP_EOL;
  
}else{
  
  // Not time to run yet.. exit
  $seconds = ($nextTime - time());
  $timeRemain = getMins($seconds);
  echo 'Not time yet.. '.$timeRemain.' ('.$seconds.' seconds) remaining'.PHP_EOL;
  
}


function writeNewTimeDelay(){
  $newTimeDelay = ( time() + rand($GLOBALS['minDelayMins']*60, $GLOBALS['maxDelayMins']*60) ) ; // Now plus a minimum of 30 min, max 5 minutes (60*5)
  file_put_contents($GLOBALS['timeFile'], $newTimeDelay);
  return ( $newTimeDelay - time() ); // Return seconds of a delay
}

function getMins($t){
  return sprintf("%02d%s%02d", ($t/60)%60, ':', $t%60);
}
?>