I am attaching text of General Clauses Act 1897 for your information.
Section 10 of the Act is very important and many of us are not aware of this provision. It provides that if the due date for payment of any amount under any Act falls on a holiday, next working day will be deemed to be the due date. Similiarly, if any return is to be filed with the govt. and the due date is a holiday, then the next working day will be deemed to be the due date.
It is applicable to all payments such as PF, ESIC, excise, service tax, income tax etc. etc. Suppose due date for payment of PF is 15th which is holiday, then next working day (i.e. 16th) will be the due date. No action can be taken by the govt. authorities since it is well within the prescribed time.