Meaning of phrase "last working day of second preceeding month"

while filling form NDH 1 in respect of nidhi companies, in point 7 it says "deposits outstanding at the close of 
business on the last working day of the 
second preceding month".
i cannot understand meaning of this sentence.
last month of a financial year is march, first preceeding month is february, so second preceeding month is january. so are they talking about last working day of january ?
i have seen same phrase in many rbi circulars also.
can anybody please help me.