Any ways to show items with data set to today?

I often use dates to mark something with dead line.

Looking through all the documents to find such items is a pane.

Is there a way to see items on a timeline?

There is no timeline. If you want such out of dynalist, I think your best option is integrating with something like Google calendar. Your dated items will be automatically exported, and there you can see a time line.

Within dynalist, there are search operators, so you can type in search things like within:1d to see all tasks due within 1 day.

You can find documentation on both these for more details.