Add Date module

[jdharrisnz]

Type

• [ ] Refactor
• [X] Feature
• [ ] Bug Fix
• [ ] Optimization
• [ ] Documentation Update

Description

Add Date module.

Related

N/A

Questions from me

Hi, my first time contributing to this! Hopefully this module is valuable and well-written.

I had some questions about code style and documentation.

First - @since tags - who adds these? I don't think I can do it since I don't know which version this might be added to.

Second - Predicate-based dual api functions. I've never seen these in Effect, but there are a few functions that offer optional arguments with default values, such as the week functions and their dowOffset. There's no difference between these usages:

pipe(Date.create(), Date.toWeekNumber)
pipe(Date.create(), Date.toWeekNumber(1))

...and TypeScript has no problem figuring out which overload to use, but it's a bit confusing to read.

Third - Is there some requirement for test coverage? I've added tests for everything that might be considered complex, but a lot of functions are also extremely trivial.

Fourth - I've added a lot in here and surely cover all the basics, but there's surely also more inspiration I could take from projects like date-fns. How comprehensive is something like this expected to be before it's accepted?

Thanks!