Document cross-language comparison

[ptomato]

Originally from tc39/proposal-temporal#105

How does Temporal compare to date-time libraries in other programming languages, and to JavaScript date-time libraries in the ecosystem?

C#

• DateOnly
• DateTime
• DateTimeOffset
• TimeOnly
• TimeSpan
• TimeZoneInfo
• For .NET, NodaTime
• in-progress .NET equivalent to ZonedDateTime

Java

The joda-time library that resulted in JSR-310 and became part of the language in Java 8.

Comparison already done: http://widdindustries.com/ecma-temporal-vs-java-time/

JavaScript

• date-fns (docs)
• Moment.js
• Luxon
• dayjs

Brief overview of the JS libraries above: https://github.com/you-dont-need/You-Dont-Need-Momentjs#brief-comparison

PHP

• DateTime (built-in)
• Carbon
• (+ every larger PHP framework rolls their own, but not sure if relevant to include...)

Python

• datetime (built-in)
• zoneinfo (built-in, Python 3.9+)
• dateutil
• arrow

Rust

• chrono
• https://github.com/rust-lang/rust-wiki-backup/blob/master/Lib-datetime.md