Also, I am not sure but some of the other agencies who do tax preparation say's, if in the current tax year (let say 2019) if person has not completed 6 months but he/she will going to continue to stay more than next 6 months (2020), then he/she will be eligible for 1040 for 2019 tax year.
I am not sure this information is correct or not. but this is what i have got from some of tax portals.
