Tax returns are not due until April 15, but the Internal Revenue Service says the two weeks after President’s Day is historically the peak time when taxpayers call the agency for help. The IRS is encouraging taxpayers who need help to use its online tools before they call the agency for help. Taxpayers can avoid phone delays during the “anticipated peak demand for IRS phone lines” by first checking the agency’s step-by-step help guide before calling. The guide highlights popular topics and instructs taxpayers on how to check if they need to file, what documents are needed, which credits and de…