<!DOCTYPE html>
<html>
<head>
<link data-require="bootstrap-css@3.3.1" data-semver="3.3.1" rel="stylesheet" href="//maxcdn.bootstrapcdn.com/bootstrap/3.3.1/css/bootstrap.min.css" />
</head>
<body style="margin: 2em;">
<div class="alert alert-danger hidden-sm">
Bootstrap's <code>form-inline</code> CSS class only works on <code>xs</code>-viewports (< 768px).<br/>
Make this window/frame bigger to see <code>form-inline</code> in work.
</div>
<div class="form-inline">
<div class="form-group">
<label for="from">Valid from</label>
<p class="input-group">
<input type="text" id="from" class="form-control"/>
<span class="input-group-btn">
<button type="button" class="btn btn-default"><i class="glyphicon glyphicon-calendar"></i></button>
</span>
</p>
<label for="to">to</label>
<p class="input-group">
<input type="text" id="to" class="form-control"/>
<span class="input-group-btn">
<button type="button" class="btn btn-default"><i class="glyphicon glyphicon-calendar"></i></button>
</span>
</p>
</div>
</div>
<div class="form-inline">
<label for="another-input">Another Element</label>
<input type="text" id="another-input" class="form-control"/>
</div>
</body>
</html>
See http://paul.wellnerbou.de/2015/06/15/aligning-form-elements-in-one-line-using-bootstraps-grid/