Exercise $6\mathrm{.}7$ Given a month and a year, the Unix cal command produces a calendar for that month; for example, cal $101752$ produces

Code download

Given a year, as in cal $2000,$ the output is a calendar for that year.

Your task is to design a modular architecture for a proposed implementation of the cal command. $($See instructions below.$)$

a$)$ List the modules in your architecture. Design each module so it has a coherent responsibility and so it can be modified independently of the others. Use descriptive names for the modules.

b$)$ Provide a brief overview of how the modules interact to produce the calendar for a month.

c$)$ Provide a view guide that consists of a module hierarchy and an element catalog.

Here are some instructions:

$-$ Allow for your version of cal to be modified, if needed, to produce dates in the European style, with Monday as the first day of the week in the calendar for a month. Note that the preceding example is in the US style, with Sunday as the first day of the week. The format for a yearly calendar has yet to be determined.

As a simplification, your design must work for months starting October $1752$ and full years starting $1753.$ Thus, the start date for your calendar is Sunday, October $1,1752.($The US calendar changed in September $1752$: the month had only $19$ days instead of the usual $30.)$

$-$ Note that this exercise is about a modular software architecture, not its implementation.