Example Date Time Formatting

index.php

<?php
//Creates a formated string from a start and end date DateTime, a start and end time DateTime, and optional DateTimeZone.

function formatDateRange($d1, $d2, $t1, $t2, $tz=false) {
	if(gettype($t1) === 'object' && gettype($t2) === 'object'){
		$formatted_time = "";

		if($tz && preg_match('/(\-|\+)[0-9]*/', $tz->getName() )){
      //use 24 hour time for EMEA
			$hour_format = 'G';
			$ampm = false;
			$time_zone = $tz->getName();
			$t1->display_minutes = ':i';
			$t2->display_minutes = ':i';
		}
		else{
			$hour_format = 'g';
			$ampm = ' A';

			$time_zone = ($tz ? ' '.$tz->getName() : false);
			$t1->display_minutes = ($t1->format('i') === '00' ? '' : ':i');
			$t2->display_minutes = ($t2->format('i') === '00' ? '' : ':i');
		}


		if ($d1->format('Y-m-d') === $d2->format('Y-m-d')) {
			//if it's the same day, show the time
		  if ($t1->format('h:i') === $t2->format('h:i')){
				//same hour and minute
				$formatted_time = $t1->format('g'.$t1->display_minutes.' ');
			}elseif($t1->format('h') === $t2->format('h')){
				//same hour of the day
				$formatted_time = $t1->format($hour_format.$t1->display_minutes).' - '.$t2->format($hour_format.$t2->display_minutes.$ampm);
			}
			elseif($t1->format('a') === $t2->format('a')){
				//same meridian
				$formatted_time = $t1->format($hour_format.$t1->display_minutes).' - '.$t2->format($hour_format.$t2->display_minutes.$ampm);
			}else{
				$formatted_time = $t1->format($hour_format.$t1->display_minutes).' - '.$t2->format($hour_format.$t2->display_minutes.$ampm);
			}

		}else{
			//different_days -
			$formatted_time = false;
		}

	}
	if(gettype($d1) === 'object' && gettype($d2) === 'object'){
    if ($d1->format('Y-m-d') === $d2->format('Y-m-d')) {
        # Same day
        return $d1->format('M j, Y').(isset($formatted_time) ? ' | ' : '').$formatted_time.$time_zone;
    } elseif ($d1->format('Y-m') === $d2->format('Y-m')) {
        # Same calendar month
        return $d1->format('M j') . $d2->format(' – j, Y');
    } elseif ($d1->format('Y') === $d2->format('Y')) {
        # Same calendar year
        return $d1->format('M j') . $d2->format(' – M j, Y');
    } else {
        # General case (spans calendar years)
        return $d1->format('M j, Y') . $d2->format(' – M j, Y');
    }
	}else{
		return false;
	}
}

//Example with start and end date and time ACF fields and a timezone acf field.

$dt_array = array(
		'start_date' => DateTime::createFromFormat('F j, Y', get_field('start_date', $post_id)),
		'end_date' => DateTime::createFromFormat('F j, Y', get_field('end_date', $post_id)),
		'start_time' => DateTime::createFromFormat('g:i a', get_field('start_time', $post_id)),
		'end_time' => DateTime::createFromFormat('g:i a', get_field('end_time', $post_id))
	);

if(get_field('time_zone', $post_id)){
		$tz = new DateTimeZone( get_field('time_zone', $post_id));
	}else{
		$tz = '';
	}

$date_str = formatDateRange($dt_array['start_date'], $dt_array['end_date'], $dt_array['start_time'], $dt_array['end_time'], $tz);