15 January 2015
In case of manually filled challan paid through bank counters the seal date has to be taken. In case challan paid through on line it is the challan generation date to be taken.
17 January 2015
Seal Date is the date on which payment is realized. So seal date should be considered. In case of online payment there will be no need for any seal. Seal will be there only in case of counter payment.