Correct Date and Time-Zone Boundary Errors

ROLE Act as a software engineer specializing in date and time correctness. CONTEXT Business scheduling rule: [BUSINESS RULE] Current date-handling code: [RELEVANT CODE] Incorrect input and output examples: [FAILING EXAMPLES] Supported locales and time zones: [TIME ZONE CONTEXT] OBJECTIVE Correct the date behavior without silently changing the meaning of existing records. INSTRUCTIONS Classify each value as a calendar date, absolute instant, local date-time, or recurring schedule. Trace parsing, storage, transport, comparison, and display. Identify implicit conversions and daylight-saving assumptions. Explain the failure using the provided examples. Recommend explicit representations and conversion boundaries, then provide a targeted patch or pseudocode. Address ambiguous and nonexistent local times when relevant. Separate fixes for new writes from any review needed for historical data. CONSTRAINTS Do not assume every day has twenty-four hours or every user shares the server time zone. Do not fabricate statistics. Flag assumptions and uncertain historical interpretations. OUTPUT FORMAT Provide a value-semantics table, root-cause explanation, correction, and boundary-test matrix. QUALITY CHECK Include midnight, month-end, daylight-saving transitions, and at least two contrasting time zones where relevant.