Checking which button is pressed with two forms - php

Question

I have two forms in my webpage, one with a field and a button and the other with two fields and a button.
I have a hard time checking which form's button is pressed, any advice is welcome on how to handle this.
<form class="form-inline" action="somewhere.php" method="post">
<div class="form-group">
<label for="date">Date:</label>
<input type="text" class="form-control" name="date" id="date" placeholder="abc">
</div>
<button type="submit" class="btn btn-default">Submit</button>
</form>
<form class="form-inline" action="somewhere.php" method="post">
<div class="form-group">
<label for="date1">Date 1:</label>
<input type="text" class="form-control" name="date1" id="date1" placeholder="abc>
</div>
<div class="form-group">
<label for="date2">Date 2:</label>
<input type="text" class="form-control" name="date2" id="date2" placeholder="abc">
</div>
<button type="submit" class="btn btn-default">Submit</button>
</form>
And what is supposed to check what button is pressed.
$date = $_POST['date'];
$date1 = $_POST['date1'];
$date2 = $_POST['date2'];
if (!empty(date)) {
//do something
}
if (!empty($date1) && !empty($date2)) {
//do something else
}

Answer 1

First give name attribute in button.
<button type="submit" name="button1" class="btn btn-default">Submit</button>
<button type="submit" name="button2" class="btn btn-default">Submit</button>
now php side check which button is pressed:
if(isset($_POST['button1']){
//Do something.
}
else if(isset($_POST['button2'])
{
//Do something.
}

Answer 2

HTML
<button type="submit" name="btn1" class="btn btn-default">Submit</button>
<button type="submit" name="btn2" class="btn btn-default">Submit</button>
PHP
if(isset($_POST['btn1']){
//put code here.
}else{
//put code here.
}