How to let dashboards automatically refresh
If you want dashboards to show running changes—that is, to show new data soon after it’s available—you can set your reporting period to use the auto-refresh option.
When setting the reporting period during your Apex session, dashboards show you metrics observed during that time frame. If you continue viewing a dashboard like this, without navigating elsewhere in Apex and then returning to the same dashboard (which triggers a refresh), the dashboard sits idle and shows the same data it originally fetched. However, with the auto-refresh option enabled, the dashboards you are viewing can update automatically.
Auto-refresh only happens when a dashboard is in focus. Dashboards with a reporting period of one hour or less refresh once a minute. Dashboards whose reporting period is longer than one hour refresh every 10 minutes.
Caution: Viewing a dashboard while auto-refresh is enabled will suspend Enable Session Timeout for as long as it is in view. In this specific scenario, the inactive user will not be signed out of Apex.
To let dashboards automatically refresh:
1. Run a dashboard from the leftmost pane by clicking it or by following a dashboard workflow.
2. In the upper-right corner under Admin, click
The refresh button changes to the color blue.
 
With Auto-Refresh now enabled, a dashboard being viewed updates and displays new data automatically.
 
 
For more information about auto-refresh operates, see Understanding dashboard auto-refresh.