'The station uses New Zealand time (UTC+12 during standard time and UTC+13 during daylight saving time) since all flights to McMurdo station depart from Christchurch and, therefore, all official travel from the pole goes through New Zealand.'
Great job building this and also writing the documentation that explains concepts as well as how they are implemented.
I can't believe how many comments here are dismissive. If you are happy using a paid solution to manage your finances and don't want to get into the weeds yourself, you are probably not the target audience for this.
One suggestion would be to make the country-specific pieces like tax calculations module so others can contribute their own.
> how hard is it to pay in cash or to get service as anything but a light skinned person in a japan convenience store?
There is close to zero overt racism of the sort you're referring to.
In almost any Japanese customer service situation involving big companies, the smiles and friendly demeanor are mostly a facade for a very transactional relationship.