Articles completion formality in Form 108

Hello, i had taken transfer from my first principal period 19/09/2007 to 31/03/2008

Second principal - 24/05/2008 to 19/04/2011.

so can anyopne tell while filling my form 108 will i write date of commencement of training  as 19/09/2007 or 24/05/2008

and whther total period of whole article or under second principal is to be mentioned???