I have a DACA work permit now, but it expires on March 8, 2018. That is just a few days past the March 5, 2018 date that would have allowed me to renew DACA under the Trump administration's latest plan to end the program.
So, I'm getting used to the idea that I will have to leave my job in less than a year. But when, exactly, do I have to leave? On March 8? Or even before, like on March 7, or whenever my employer figures out that I have DACA and fires me?
First off, you are correct in your analysis that the new Trump policy does not allow you (based on the facts you've provided) to submit a renewal DACA (Deferred Action for Childhood Arrivals) application.
U.S. Citizenship and Immigration Services (USCIS) is accepting renewal applications only from DACA recipients whose benefits expire between September 5, 2017 and March 5, 2018 (on condition that it receives their applications by October 5, 2017).
Now, you say that your employment authorization document (also called an EAD or work permit) expires on March 8, 2018. That means that you can literally work the entire day of March 8. You do not need to leave your job even one day earlier.
What's more, your employer should NOT be taking steps to pressure or fire you before that date. Your employer should, by law, be limiting its oversight of your immigration status to simply keeping track of when your work permit expires and letting you know that it will need to see a renewed work authorization in order for you to continue working past that date.
The employer has no legitimate reason to go looking deeper into whether you have DACA. In fact, taking action (such as firing you or changing your job) based on hearing information about your DACA status could be seen as unlawful discrimination based on citizenship or immigration status. If you feel your employer is being overly inquisitive or taking steps toward an action such as termination, by all means consult with an experienced employment law attorney.
It would also be worth checking in with an immigration attorney, for a full personal analysis of whether you qualify for some other form of immigration benefit or even a green card (lawful permanent residence). Also, to allay your possible concerns, read "With Trump Ending DACA, Will I Be Deported?".
And finally, don't forget that Congress still has time to act. Keep your eye on the news, and for any possible program to ease the transition for people losing DACA status.