`Mark of Credit, Counting the Days, Numismatrix

Can anyone explain what this mechanic is all about, what i can or should gain from it? i’ve got my counting the days up to 14 now and a number of choices.

Mark of Credit is the most important thing here.

The end goal of Counting the Days is to acquire an Iron-Republic Safe Conduct for access to said location by trading in 3 Marks.
The secondary goal is to trade it for a Consonant Violin, which is the only Respectable weapon and can be used for free Connected: Masters during Christmas. There are better BDR weapon though.

Other options are not very good, but once you are done with the above the Surface Currency options give the best cash reward and it is an viable alternative source for First City Coins.