Sentence:  However , if their United States income is not subject to the withholding of tax on wages , their returns are due June 15 , 1962 , if they <WSD>use</WSD> a calendar year , or the 15 th day of the 6 th month after the close of their fiscal year . 
Meaning of the word marked with <WSD> tags:  put into service; make work or employ for a particular purpose or for its inherent or natural purpose