I was working in US on H1B visa. I left US on Jan 16-2020 and continued to work for the same employer till April 2020 from outside US (remotely). I couldn't return back to US due to pandemic. Though I was in US payroll till APRIL 2020, I was physically present in US 16 days only. So, what part of my income is taxable ? only 16 days of earning ? or whole of my earning till APRIL 2020 with US employer?
Note: I am assuming I have to file 1040NR because I was not present at least 31 days in the US.