Sir,
The newly inserted proviso states that-
3. "In the said rules, in rule 4, -
(a) in sub-rule (1), after the second proviso, the following proviso shall be inserted with effect from first day of September 2014, namely :–
“Provided also that the manufacturer or the provider of output service shall not take CENVAT credit after six months of the date of issue of any of the documents specified in sub- rule (1) of rule 9.”;"
This new proviso shall come into effect on 1.9.2014. On this date there shall be a gap of maximum six months between the date of invoice and date on which the credit is taken. If you calculate six months backwards from 1.9.2014 it will fall on 1.3.2014. Therefore according to this proviso, on 1.9.2014 if the invoice issued by the supplier of inputs on or after 1.3.2014 then it will be within six months. If the invoice is issued prior to 1.3.2014 then the credit shall be taken latest by 31.8.2014 for the reason the proviso will come into effect from 1.9.2014.