我应该如何将减去的分钟转换为unix时间戳

Question

<div class="container g-pt-20 g-pb-70">
                    <?php
while(!$Recordset1->atEnd()) {
?>
 <div class="row g-bg-gray-light-v4 g-pa-30 g-mb-30" style="border: thin #1A0203; border-radius: 5px"> 

                      <div class="col-md-7">
                        <h2><?php echo($Recordset1->getColumnVal("TITLE")); ?></h2>
      <?php echo($Recordset1->getColumnVal("DESCRIPTION")); ?>
                      </div>

                      <div class="col-md-3">
                        <?php if($Recordset1->getColumnVal("IMAGE") != "") {         
?>
 <img src="images/<?php echo($Recordset1->getColumnVal("IMAGE")); ?>" class="img-fluid mx-auto d-block" alt=""/>  <?php } 
?>
                      </div>
                        <div class="col-md-2 g-color-black">
                          <?php echo($Recordset1->getColumnVal("TIMESPAN")); ?> | $<?php echo($Recordset1->getColumnVal("COST")); ?><br><br>
                          <a href="#fancybox-form<?php echo($Recordset1->getColumnVal("ID")); ?>" data-fancybox-speed="350" class="js-fancybox btn btn-md u-btn-indigo g-mr-10 g-mb-15">BOOK NOW</a>

                        </div>
                      </div>

<div id="fancybox-form<?php echo($Recordset1->getColumnVal("ID")); ?>" 
class="clearfix rounded-0 g-pa-30 w-50" 
style="display: none; min-width:400px;">
<form class="form-horizontal" method="post" name="fancybox-form">
<fieldset>

<!-- Form Name -->
<legend>Request A Day and Time - <?php echo($Recordset1->getColumnVal("TITLE")); ?></legend>
<input type="hidden" id="ID" name="ID" value="<?php echo rand(111,999999); ?>">
<input type="hidden" id="TITLE" name="TITLE" value="<?php echo($Recordset1->getColumnVal("TITLE")); ?>">
<!-- Text input-->
<div class="form-group">
<label class="col-md-4 control-label" for="NAME">Your Name</label>  
<div class="col-md-7">
<input id="NAME" name="NAME" type="text" placeholder="" class="form-control input-md" required oninvalid="this.setCustomValidity('Please enter your name')"
 oninput="setCustomValidity('')">  
</div>
</div>

<!-- Text input-->
<div class="form-group">
<label class="col-md-4 control-label" for="EMAIL">Your Email</label>  
<div class="col-md-7">
<input id="EMAIL" name="EMAIL" type="email" placeholder="" class="form-control input-md" required oninvalid="this.setCustomValidity('Please enter a valid email address')"
 oninput="setCustomValidity('')">

</div>
</div>

<!-- Text input-->
<div class="form-group">
<label class="col-md-4 control-label" for="PHONE">Your Phone</label>  
  <div class="col-md-7">
  <input id="PHONE" name="PHONE" type="text" placeholder="" class="form-control input-md" required oninvalid="this.setCustomValidity('Please enter your phone number')"
 oninput="setCustomValidity('')">

  </div>
</div>

<!-- Text input-->
<div class="form-group">
  <label class="col-md-4 control-label" for="DATE_REQ">Date Requested</label>  
  <div class="col-md-7">
  <input id="DATE_REQ" name="DATE_REQ" type="text" placeholder="" class="form-control input-md" required oninvalid="this.setCustomValidity('Please enter the date you would like to visit')"
 oninput="setCustomValidity('')">

  </div>
</div>

<!-- Text input-->
<div class="form-group">
  <label class="col-md-4 control-label" for="TIME_REQ">Time Requested</label>  
  <div class="col-md-7">
  <input id="TIME_REQ" name="TIME_REQ" type="text" placeholder="" class="form-control input-md" required oninvalid="this.setCustomValidity('Please enter your appointment time')"
 oninput="setCustomValidity('')">

  </div>
</div>

<!-- Textarea -->
<div class="form-group">
  <label class="col-md-4 control-label" for="textarea">Comments</label>
  <div class="col-md-7">                     
    <textarea class="form-control" id="textarea" name="textarea"></textarea>
  </div>
</div>

<!-- Button -->
<div class="form-group">
  <label class="col-md-4 control-label" for="bookappt"></label>
  <div class="col-md-7">
   <div class="g-recaptcha" data-sitekey="6LdQYRIUAAAAAC020yhPUryaBGst2upxlTSqigqo"></div> <br>
<button id="bookappt" name="bookappt" class="btn btn-success">Send Your Request</button>
  </div>
</div>

</fieldset>
</form>

                        </div>

                    </div>
                      <?php
  $Recordset1->moveNext();
}
$Recordset1->moveFirst(); //return RS to first record
?>

  

差异是约。 15分钟