Is it possible to add current timestamp as a visualization to my dashboard?
If yes , then how can we do it.
Interesting question, I can't think how you would do this, so I think the answer is no. At least for now. In the future, Kibana visualizations will work a lot of Canvas elements, being driven by an expression that can fetch and display time data. So while I don't think you can do that today, that functionality is coming and should land in the 7.x line some time.