I entered US from Indian in the first week of DEcember and I applied for an SSN during mid December and they have held it for want of more information and I will have to wait for up to 4 weeks before I know if I get an SSN. In such a case how can I file for my tax returns, my employer may put in a temperory SSN id on my W2 form. Should I wait for the SSN or is there any other way to proceed. What is the last day of filing for Tax returns?