The tax filing season for 2013 income taxes will open January 31, 2014, according to the IRS.
Extensions and tax returns may begin to be electronically filed at that time, but if the experience of the last two years is any indication, the IRS systems will be overloaded and filing will be delayed for another day or so.
The normal filing deadline of April 15 for personal income taxes falls on Tuesday this year, so do not expect any extra filing days. When in doubt, the safe bet is to file an extension!