http://wordpress.org/plugins/skip-to-timestamp/

Skip to Timestamp allows two ways of generating links in your posts that automatically skip to a given time in an embedded media element. You've seen it in the Youtube descriptions, now get it in your embeds!

To create a link, either:

• Use our [skipto] shortcode which takes a "time" (or "timestamp" or "ts") argument and uses that to create a link. Eg, "Just wait until...or...hold on, you can [skipto time=4:30]skip to[/skipto] this part of the video!"
• Check the "Replace Timestamps Automatically" checkbox in the Settings > Skip to Timestamp, and watch as all your timestamps in the form "4:30" or "1:23:45" are automatically converted into links.

The links search for and skip to a time in:

• Youtube videos embedded using Wordpress embeds.
• HTML5 <audio> elements. Jetpack, Blubrry Powerpress and other plugins do this automatically using the [audio] shortcode.
• HTML5 <video> elements. Jetpack and other plugins do this automatically using the [video] shortcode.

You don't really need to do anything special to install this plugin. Just:

1. Download using the button above, unzip and place the folder in your wp-content/plugins/ folder. Alternately, install using Wordpress' built-in plugin installer.
2. Activate the plugin through the Plugins menu in WordPress
3. Configure settings via Settings > Skip to Timestamp. Automatic timestamp replacement is turned off by default.

If it adds an <audio> or <video> tag, then probably. The plugin uses the currentTime parameter of those elements to set the location to skip to. If you open your browsers developer console and see a message saying 'Skip to Timestamp: No media player found!', then that player isn't currently supported. I'd like to help you though, so please submit a request for that player on the Wordpress plugin page. It's the only way I know which players to prioritise!

Yes, as long as you don't use both in the same post. Each post can contain either shortcodes OR timestamps to auto-replace. If both are present, then timestamps will not be automatically replaced.

Make sure the Link only on singular posts/pages setting (Settings > Skip to Timestamp) is unchecked.

Leave a ticket either here or on the WP plugin page with information about the media you embedded, how you tried to create the link, and what browser and operating system you're running. If it's a bug, I'll get right to work on it!