I cant do much for others if today is my last day. This also means I failed my previous days if the thought of thinking for others just came in my last day.
However, I can do enjoy reading Darwin evolotion related books and Harari' Sapiens, to question, if my anchestor's cognitive function didnt develop I may not even know today is my last day. Why bother thinking this is my last day? Just go through the day.
Though I may try to go to the mountain and enjoy the scenery. Smile there alone the whole day.