[Python] Implement missing DateTimeOffset members, add DateOnly and TimeOnly

[dbrattli]

Summary

• Implement missing DateTimeOffset members for the Python target, closing Implement missing DateTimeOffset functionality for the Python target #4475
• Add DateOnly and TimeOnly support (new date_only.py and time_only.py)
• Fix DateTimeOffset equality/comparison to use UTC-normalized instants (.NET semantics)
• All 2193 Python tests pass (21 new); 78 .NET tests pass; 0 Pyright errors

DateTimeOffset — new members

Constructors: FromDate(DateTime), FromTicks(int64, TimeSpan), DateTimeOffset(DateOnly, TimeOnly, TimeSpan)

Fields: MaxValue, UnixEpoch

Properties: UtcDateTime, LocalDateTime, Date, DayOfWeek, DayOfYear, TimeOfDay, Ticks, UtcTicks, TotalOffsetMinutes

Methods: Add, AddYears/Months/Days/Hours/Minutes/Seconds/Milliseconds/Ticks, ToUniversalTime, ToLocalTime, ToOffset, Subtract, Compare, CompareTo, EqualsExact, FromUnixTimeSeconds/Milliseconds, ToUnixTimeSeconds/Milliseconds

Operators: op_Addition

DateOnly — new

Constructors, MinValue/MaxValue, Day/Month/Year, DayOfWeek, DayOfYear, AddDays/AddMonths/AddYears, ToDateTime, ToString, Parse/TryParse, FromDateTime

TimeOnly — new

Constructors, MinValue, FromTicks, FromTimeSpan, FromDateTime, Hour/Minute/Second/Millisecond, Ticks, ToTimeSpan, Add, AddHours/AddMinutes, IsBetween, ToString, Parse/TryParse, op_Subtraction

Key fixes

• DateTimeOffset equality/comparison routes to date_offset module (UTC-normalized)
• FromUnixTimeSeconds/Milliseconds call proper date_offset functions
• from_date_time_offset in date.py returns plain datetime (not DateTimeOffset subclass)
• DateTimeOffset.__sub__/__add__ overrides prevent wrong constructor dispatch
• Unsafe thisArg.Value replaced with pattern matching in Replacements.fs

Test plan

• 2193 Python tests pass (0 regressions, 21 new)
• 78 .NET tests pass (DateTimeOffset + DateOnly + TimeOnly)
• 0 Pyright errors on all library files
• Changelogs updated

🤖 Generated with Claude Code

[github-actions]

Python Type Checking Results (Pyright)

Metric	Value
Total errors	18
Files with errors	4
Excluded files	4
New errors	✅ No

Excluded files with errors (4 files)

These files have known type errors and are excluded from CI. Remove from pyrightconfig.ci.json as errors are fixed.

File	Errors	Status
temp/tests/Python/test_applicative.py	12	Excluded
temp/tests/Python/test_hash_set.py	3	Excluded
temp/tests/Python/test_nested_and_recursive_pattern.py	2	Excluded
temp/tests/Python/fable_modules/thoth_json_python/encode.py	1	Excluded

[ncave]

@dbrattli While you're at it, perhaps also fix the create to match the microsecond constructor, since the underlying object supports microseconds storage.