Last-minute tax filers have two more days to procrastinate.

The Internal Revenue Service has postponed Tax Day to Tuesday, April 17. That’s because the traditional filing deadline of April 15 falls on a Sunday.

Typically, the deadline would be the following day, but April 16 is Emancipation Day, a public holiday in Washington, D.C., which is treated as a federal holiday.

But those who plan to drive on Tuesday to the post office or their accountants should take extra caution on the road. Researchers from Sunnybrook Research Institute in Toronto looked at 30 years worth of U.S. highway data and found a six percent increase in the number of fatal car crashes on Tax Day, compared to a week before and after. That’s an average of 13 more deaths.

Researchers can’t explain the uptick in certain terms, but they believe that “stressful deadlines might increase the risk of road trauma by impairing drivers.” Their report was published Wednesday in the Journal of the American Medical Association.

Perhaps Benjamin Franklin saw this coming when he said, “In this world nothing can be said to be certain, except death and taxes."