Sequences, Master View Timeline

[bmachia]

I am trying to learn about Sequences, specificity the Master View, Timeline.
How do I control (i.e. make changes) to this timeline.  Like Increase or decrease the overall time at the top and what is that Hatched Area?  How did it get there?

I will try my best to explain.  (I admit, I do not understand what I am asking).  I created a Sequence that has a crawling text message.  The message starts at the zero second point and ends at 12 seconds.

I am looking at the Master View Timeline.  It starts at 0 seconds and expands out to (approximately) 46 seconds.
At the 30 second mark, Hash mark area appears and continues to the 46 second end point.

How did I adjusted this time to 46 seconds.  Was it a Control Key?  Alt Key?  A Scroll Wheel?
Where did these Hash marks come from?
   What do they mean?
   What did I do to put them there?
   I also cannot seem to drag, move, or change these.

Could someone point me to a section in the Manual that explains this?
Are there any YouTube video?s I might benefit from?

Thanks for helping a newbie and Thank You for reading my post.
Bill

[allknowing2012]

The timing is based on the length of the audio - or in this case if it is an animation, it defaults to 30s. To change this File->Sequence Settings. The length is there.

[Gilrock]

You can set the time when you create an Animation sequence but it defaults to 30 sec if you don't change it.  The program will allow you to have effects past the end of the sequence but they get ignored after the cutoff time.  So when someone shortens a sequence length we don't delete any effects.  It also allows you to have an effect at the end that runs partway through.