You can determine a time you'd like your viewers to start watching from, right from your site's URL.
Your link will look something like this http://mywebsite.com/?fromTime=YOUR_TIME, in which YOUR_TIME is expressed in seconds.
Keep in mind:
If YOUR_TIME is a valid value (a positive integer), then the viewer will be sent to that specific time on video
If YOUR_TIME exceeds the total duration of video, then the viewer will be sent to the end of video
If YOUR_TIME is 0 or any dummy value, then this invalid query parameter (?fromTime=ANY_DUMMY_VALUE) will be removed from the URL and playback will start from the beginning of the video