Like Torii said, right now it's 2019- the RP follows the present year we are in. And yeah, most of the time you will see it keep switching dates (e.g. December 12th, 2019 to October 16th, 2019) because the RP time goes faster than real time of course. So they have to switch it back to the IRL month we are in sometimes.
Can't really give an explanation on why we have flip phones since im bad at explaining, but someone will answer that sooner or later for you.