Sentence:  ( 1 ) your reasons for requesting an extension , ( 2 ) whether you filed timely income tax returns for the 3 preceding <WSD>years</WSD> , and ( 3 ) whether you were required to file an estimated return for the year , and if so whether you did file and have paid the estimated tax payments on or before the due dates . 
Meaning of the word marked with <WSD> tags:  a period of time containing 365 (or 366) days