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タイムスタンプ変換
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Learn how JavaScript represents time with Date, Date.now(), and Unix seconds. This tutorial covers converting milliseconds to seconds, turning epoch values into readable dates, formatting UTC safely, and avoiding timezone surprises in browser and Node.js code. It includes copy-ready examples for parsing input, serializing API payloads, and testing boundary cases. Use the inline converter to check a value while you read, then open the complete guide for production patterns and practical debugging advice.

Work confidently with Python timestamps using datetime, timezone-aware objects, and Unix epoch helpers. The tutorial explains seconds versus milliseconds, converting values to UTC, formatting dates for APIs, and handling daylight-saving boundaries. Examples use the standard library and show reliable patterns for scripts, ETL jobs, and web services. Try a value in the inline converter, then follow the full walkthrough to understand parsing, validation, precision, and the small details that keep timestamp pipelines consistent.

Translate Unix timestamps into database-native dates with practical SQL for MySQL, PostgreSQL, SQLite, SQL Server, and Oracle. Learn how to extract epoch seconds, format results, compare intervals, and preserve timezone meaning when data moves between systems. The guide highlights portable concepts alongside vendor-specific functions, with examples you can adapt to queries and migrations. Use the inline converter for a quick sanity check, then open the tutorial for production-ready timestamp workflows.