Janet is a cash-basis calendar-year taxpayer. She received a check for services provided in the mail during the last week of December. However, rather than cash the check, Janet decided to wait until the following January because she believes that her delay will cause the income to be realized and recognized next year. What would you tell her? Would it matter if she didn't open the envelope? Would it matter if she refused to check her mail during the last week of December? Explain.