DurationCalculator : calcRelativeDuration(String relativeDurationID) not working at all in SNOW

[ashish_dadhich]

The below utility is not working in SNOW. 

https://developer.servicenow.com/dev.do#!/reference/api/washingtondc/server_legacy/c_DurationCalcula...

var dc = new DurationCalculator();
gs.info("CurrentDuration -  "+ dc.calcRelativeDuration(currentDuration));

Is there any way by which I can get the cmn_relative_duration and add a few days into it?