Pictures from a fourth day of protests in LA

[cubezero3]

Here are some of the latest pictures from a fourth day of protests in Los Angeles.

Los Angeles live: 700 marines to be deployed - as thousands of troops 'given no food or water'

More protests are planned in LA today, demanding the end of ICE immigration raids. Donald Trump's government has controversially deployed the National Guard - prompting California to sue his administration - while the Pentagon is to deploy 700 marines. Follow the latest below.

news.sky.com

My initial thought was that the use of an indefinite article here was incorrect. We all know which day was the fourth day.
Then I started to see why this could make sense. The post was one of many possible slices of report on what happened on that day, giving we live in the era of social media. By using the indefinite article, the writer essentially says they're giving the reader a snapshot of that day.
Perhaps this is just incorrect and I'm reading too much into it?
I'd like to hear your opinions.

 

[jutfrank]

No, I think you've got it, more or less. The key is the idea of possible worlds. There can be imagined multiple possible fourth days and this fourth day, the real one, is just one of them.