In the sentence above, why is "'s" used? Is it considered a possessive? It seems strange to state that the news "belongs" to today or the history "belongs" to tomorrow.
In a comment, BillJ wrote:
They are genitive case nouns, of which possession is just one meaning. Your examples belong to a sub-type of 'attributive' genitive called 'descriptive' genitives -- other examples include "a summer's day" and "a Sainsbury's catalogue". Another sub-type is the 'measure' genitive, which includes such examples as "an hour's delay", "one dollar's worth of chocolates".