<label for="start">Start month:</label>
<input type="month" id="start" name="start"
min="2018-03" value="2018-05">
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title></title>
</head>
<body>
<label for="start">Start month:</label>
<input type="month" id="month" name="month"
min="2018-03" value="now">
<input type="submit" value="Envoyer">
<?php var_dump($_POST['month') ?>
</body>
</html>
<?php include('login.php');?>
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title></title>
</head>
<body>
<form action="pickermois.php" method="POST" name="month">
<label for="start">Mois</label>
<input type="month" id="month" name="month"
min="2020-06" value="now">
<input type="submit" value="Envoyer">
</form>
<?php
if (isset($_POST['start'])) {
$timestamp = strtotime($_POST['start']);
$month = date('n', $timestamp);
$sql = "SELECT date_format(Date,'%m/%Y ') AS Datum, TmpExt_Min, FROM Meteo_Mois WHERE MONTH(Date) = ('$month') ORDER BY ID DESC LIMIT 1";}
$result = mysqli_query ($connect,$sql);
while($row=mysqli_fetch_assoc($result))
echo "{$row['TmpExt_Min']} C°";
?>
</body>
</html>