Add datetime chapter

[RamonRDR]

Summary

• add Phase 8 Chapter 02, Working with Dates and Time Calculations Using datetime, in English, Brazilian Portuguese, and Spanish
• teach date, time, datetime, timedelta, parsing, formatting, ISO-oriented helpers, naive versus aware datetimes, UTC, fixed offsets, timezone conversion, timestamps, and deterministic time calculations
• explain important boundaries such as timedelta.seconds versus total_seconds(), fixed durations versus calendar months, astimezone() versus replace(tzinfo=...), and fixed offsets versus geographic time zones
• introduce zoneinfo conceptually without making deterministic examples depend on an external timezone database
• add four deterministic executable examples
• link Chapter 01 forward to Chapter 02
• synchronize the Phase 8 indexes, repository status pages, learning paths, roadmaps, project-structure documents, and approved example manifest
• mark json beyond basic persistence as the next planned chapter

Validation

• 35 fenced Python blocks are identical across EN / PT-BR / ES and syntax-checked with ast.parse
• 4 new executable examples, raising the approved manifest from 124 to 128 examples
• 11 repository unit tests passed
• all 128 approved examples passed
• 1,956 internal Markdown links across 199 Markdown files checked successfully
• repository structure validation passed
• git diff --check and Python compilation passed
• exactly 26 changed files
• one focused commit based exactly on main at 3b9279641ba18e2fceb6eab8b264718c9fa5aea2

References

The chapter is grounded in the official Python 3.14 documentation for datetime, strftime() / strptime() format codes, and zoneinfo.

[RamonRDR]

@codex review

[chatgpt-codex-connector]

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[RamonRDR]

@codex review

[chatgpt-codex-connector]

Codex Review: Didn't find any major issues. Keep them coming!

Reviewed commit: e590ae4a8e

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