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.