erpnext/utilities/page/calendar/calendar.html

<div class="cal_body">
	<a class="close" onclick="window.history.back();">&times;</a>
	<div class="cal_toolbar btn-group">
		<button class="btn btn-small" onclick="erpnext.calendar.add_event()">
			<i class="icon-plus"></i> Add Event
		</button>
		<button class="btn btn-small" onclick="erpnext.calendar.refresh('Day')">
			Day View
		</button>
		<button class="btn btn-small" onclick="erpnext.calendar.refresh('Week')">
			Week View
		</button>
		<button class="btn btn-small" onclick="erpnext.calendar.refresh('Month')">
			Month View
		</button>
	</div>
	<div class="cal_month_head">
		<span class="cal_view_title"></span>
		<button class="btn btn-small" onclick="erpnext.calendar.cur_view.next()">
			<i class="icon-arrow-right"></i>
		</button>
		<button class="btn btn-small" onclick="erpnext.calendar.cur_view.prev()">
			<i class="icon-arrow-left"></i>
		</button>
	</div>
</div>