html добавить Mindate к DateTime-Local Picker
<form>
<label for="party">Enter a date and time for your party booking:</label>
<input id="party" type="datetime-local" name="partydate" min="2017-06-01T08:30" max="2017-06-30T16:30">
</form>
<form>
<label for="party">Enter a date and time for your party booking:</label>
<input id="party" type="datetime-local" name="partydate" min="2017-06-01T08:30" max="2017-06-30T16:30">
</form><!-- CONVERT MYSQL DATE TIME TO DISPLAY HTML INPUT[datetime-local] VALUE -->
<input type='datetime-local' name='datetime' value='<?php echo date("Y-m-d\TH:i", strtotime($details['datetime'])); ?>'>