Dear Harshvardhan the demand is absolutely correct.....as per TDS provisions interest should br calculated @ 1.5% for a month or part of the month....in ur case tds for the month of march deposited in may after 07.05.2012 hence interest is calculated for 3 months march april & may..... one month is completed on last day of the month...not day wise (30 days) as per calculation of Manikanth....hope it is clear to you n other members who calculate a month daywise....