You can see information about the history of a task right in your task window in Dart.

To see when a task was created and last updated, open it up and look for the Activity section near the end. You can show or hide this section by clicking on the carrot. To get exact time information simply hover over the timestamps.

In addition to the Activity section, you can also choose to enable properties that display when a task was created and last updated and by whom. To enable any of these properties by default for your entire workspace go to:

Settings > Properties

And then click on the property you want to show, and click the toggle next to "Show".

You can alternatively choose to just display these properties for a particular dartboard. To do this click on the layout editor in the top right of your screen and then click the "+" to add the history properties you want to see:

In list and roadmap layouts, each history type will show as an individual column:

In the board layout, you will be able to see the information just below the title of the task on the board: