Solution
You can use:
duration = X (X is in second and it will be used to display results for the past X seconds).
start_time and end_time using epoch times.
Default "no login" URL dashboard example:
https:///scportal/WebConsole.jsp?noLogin=true#dashboard:dashboardId=a4307c04-958a-461c-8e49-04b4ee406a51
Procedure: add the parameters using the ampersand and before "#dashboard:"
Recent 5 minutes:
https:///scportal/WebConsole.jsp?noLogin=true&duration=300#dashboard:dashboardId=a4307c04-958a-461c-8e49-04b4ee406a51
From 02/01/2017 to 02/02/2017 (GMT+0):
https:///scportal/WebConsole.jsp?noLogin=true&start_time=1485907200&end_time=1485993600#dashboard:dashboardId=a4307c04-958a-461c-8e49-04b4ee406a51
Note that these epoch times will be converted to use the timezone configured for the computer used to display that URL.
For a dashboard that requires the user to login you can use:
https:///scportal/WebConsole.jsp?duration=300#dashboard:dashboardId=a4307c04-958a-461c-8e49-04b4ee406a51
https:///scportal/WebConsole.jsp?start_time=1485907200&end_time=1485993600#dashboard:dashboardId=a4307c04-958a-461c-8e49-04b4ee406a51