Give a stream of consciousness and then the final answer. The 2017 United States federal budget is the United States federal budget for fiscal year 2017, which lasts from October 1, 2016 to September 30, 2017. President Barack Obama submitted a budget proposal to the 114th Congress on February 9, 2016. The 2017 fiscal year overlaps the end of the Obama administration and the beginning of the Trump administration.

Based on this passage, when does a president's fiscal year start?
To answer this question, we should know that: The 2017 United States federal budget is the United States federal budget for fiscal year 2017, which lasts from October 1, 2016 to September 30, 2017.
So, the final answer is October 1 , 2016.