Add international support for days/months

[r1chardj0n3s]

Currently only English days/months are recognised. Could be better.

[psychemedia]

There are other parsers out there that might help with this. For example:

• dateparser [docs]: "easily parse localized dates in almost any string formats commonly found on web pages" (includes foreign language detection);
• ctparse: "parse natural language time expressions in python";
• quantulum3: "Python library for information extraction of quantities, measurements and their units from unstructured text".

In passing, I also note this other template based parser (for invoices): invoice2data.