Need to change the date format for timeline graph and found solution. Accordingly updated the 2 js file for the app and restarted the Splunk, but it was not reflected in the app. I get to know the app needs to be rebuild to take effect from a solution provided in Splunk.
But the real question is how to rebuild the app in windows?
In Linux we can use this "Build the visualization by running $ npm run build", how can we do the same in windows?
I'm assuming you have already looked at the Custom Viz tutorial.
See this answer on setting the windows environment variables correctly.