web/web_timeline/static/src/xml/web_timeline.xml

<template>
  <t t-name="TimelineView">
    <div class="oe_timeline_view">
        <div class="oe_timeline_buttons">
          <button class="btn btn-default btn-sm oe_timeline_button_today">Today</button>

          <div class="btn-group btn-sm">
                <button class="btn btn-default oe_timeline_button_scale_day">Day</button>
                <button class="btn btn-default oe_timeline_button_scale_week">Week</button>
                <button class="btn btn-default oe_timeline_button_scale_month">Month</button>
                <button class="btn btn-default oe_timeline_button_scale_year">Year</button>
            </div>
      </div>
      <div class="oe_timeline_widget" />
    </div>
  </t>

  <svg t-name="TimelineView.Canvas"
       class="oe_timeline_view_canvas">
      <defs>
          <marker id="arrowhead" markerWidth="10" markerHeight="7" refX="10" refY="3.5" orient="auto">
              <polygon points="10 0, 10 7, 0 3.5" />
          </marker>
      </defs>
  </svg>
</template>