You are running on some field. Escaping from people with hay forks.

You must figure out what date it is this day, given almost no information. But the information available is enough, as long as you have access to Wikipedia.

Note that the sun is in the constellation Leo. Go to Wikipedia and check between which dates the sun is in Leo. You will find that it must be sometime between August 10 and September 15 (as the clue beneath the image states, the tropical and sidereal zodiacs are incorrect in terms of the position of the sun, IAU must be used).

Furthermore, it should be clear from the context of the riddle that this takes place during the dark ages sometime. It was also previously specified (in the story of riddle IV) that the previous tailed star (comet) was 158 years ago. Go to the “Great Comet” entry on Wikipedia and check the historic appearances of great comets. The only two comets that are 158 years apart are 1066 and 1264, thus we must now be in 1264. Clicking the comet in the picture gives the clue that it was at its brightest a week ago on the 20th, suggesting that today is the 27th. It must thus be August.