1 The phase usually lasts up to 10 minutes.  You will be in light sleep in the second stage of a non-REM sleep. Your heart rate will come down and so will your body temperature. You will soon enter deep sleep phase.
Keep records for 3 years from the date you filed your original return or 2 years from the date you paid the tax, whichever is later, if you file a claim for credit or refund after you file your return. Keep records for 7 years if you file a claim for a loss from worthless securities or bad debt deduction. Keep records for 6 years if you do not report income that you should report, and it is more than 25% of the gross income shown on your return. Keep records indefinitely if you do not file a return.
Period of Limitations that apply to income tax returns. 1  Keep records for 3 years if situations (4), (5), and (6) below do not apply to you. 2  Keep records for 3 years from the date you filed your original return or 2 years from the date you paid the tax, whichever is later, if you file a claim for credit or refund after you file your return.