- 30% of tax assessed =15 September of previous year(for Ay 2010-11 date is 15.09.2009)
- 60% of tax assessed=15 December of previous year ( For Ay 2010-11 Date is 15.12.2009
- 100% of tax assessed = 31March of previous year (For Ay 2010-11 date is 15.03.2010)
Further for capital gain amount person can pay prospective instalments only.so If you have not paid your tax pro-rata bases in advance as shown above you have to pay interest u/s 234C .Further If you have not paid your full taxes by 31.03.2010 for Ay 2010-11 then you have pay interest under section 234B on balance amount of tax .
Interest U/s 234A is payable only if you miss the Income tax due date for Ay 2010-11 ie 31.07.2010.And I hope you are not interest in calculation under this section .However the given calculator will calculate interest under this section also where ever applicable.