To specify start time and end time, this shortcut youtubestartend.html
works for me:
<div style="position: relative; padding-bottom: 56.25%; padding-top: 30px; height: 0; overflow: hidden;">
<iframe src="http://www.youtube-nocookie.com/embed/{{ index .Params 0 }}?start={{ index .Params 1 }}&end={{ index .Params 2}}"
style="position: absolute; top: 0; left: 0; width: 100%; height: 100%;" allowfullscreen frameborder="0" title="YouTube Video"></iframe>
</div>
For example to start at 1:10 and end at 1:28:
{{< youtubestartend vGjJ5p8N2nA 70 88 >}}
Improvements always welcome.