Unix Timestamp is the total number of seconds (excluding leap seconds) from 1970-01-01 00:00:00 UTC to a specified time. It is commonly used in system logs, API interfaces, and similar scenarios.

• 📌 Second-level timestamp (10 digits): Suitable for most backend systems (e.g., PHP, Python, MySQL).
• 📌 Millisecond-level timestamp (13 digits): Often used in JavaScript (Date.now() returns milliseconds) and frontend high-precision scenarios.
• 🌐 Timezone-independent: The timestamp itself has no timezone; when converted to a date, it is affected by the local timezone.
• ⚠️ This tool auto-detects: 13-digit numbers are treated as milliseconds, others as seconds; you can also manually select the unit.
• 💡 Example: 1742390400 corresponds to 2026-03-19 14:30:00 (depends on the timezone).