The number of days till March 8 varies each year based on the current date. You could count it manually by marking the days on a calendar or use an online date calculator to get an accurate count.
I'm not sure exactly how many days are left till 'Solo: A Star Wars Story' as it was released in 2018. But if you're referring to some sort of re - release or special event related to it, more information would be needed.
I haven't read this short story specifically. But generally, when analyzing a short story, one could start with the characters. Who are the main characters? What are their personalities and motives? Then look at the plot. Is it a linear plot or does it have flashbacks? Maybe there are some interesting themes like love, friendship, or the struggle for survival in the story.
I don't have that information at hand. Usually, you can calculate it by comparing the current date to the scheduled date of Comic Con 2018, which you can find on their official platform or through news related to it.
Since I don't have the actual content of the '12th of december short story', it's hard to say exactly. It might involve the experiences of the characters on that particular date. For example, it could be a love story that takes place on December 12th, with the setting and events of the day playing an important role in the development of the relationship.