Authentication Description
You can read about authentication here: 
http://www.iqengines.com/apidocs/apis/authentication.html

Authentication Debug Tool
We have created an authentication debug tool which may help.
http://www.iqengines.com/dashboard/debug/authentication/

Checking the Timestamp
For timestamp, you can check the correct timestamp from our authentication debug tool:
http://www.iqengines.com/dashboard/debug/authentication/
Also, you can run and compare that to the following command in the terminal: date -u +%Y%m%d%H%M%S