Unix Timestamp Converter

Convert Unix Timestamps to Human-Readable Dates Instantly

Log files, API responses, and database rows all store time as an integer, and every developer eventually faces a bare number like 1722758400 with no idea what date it represents. A timestamp converter bridges that gap: it turns Unix epoch seconds into readable UTC and local dates, converts dates back into timestamps, and shows the time in ISO 8601 format plus relative terms like "2 hours ago." You need it whenever you debug logs, inspect database records, build API integrations, or write tests that depend on a specific moment in time.

Understanding Epoch Seconds vs. Milliseconds

A Unix timestamp counts seconds since January 1, 1970 UTC (the epoch). Many systems, including JavaScript's Date.now(), return milliseconds instead — a number about one thousand times larger. Mixing the two is one of the most common timestamp bugs in software. Databases such as PostgreSQL commonly store time as bigint epoch values, and cloud log services export every event with an integer timestamp, so knowing which unit you are looking at matters before you trust any conversion.

When a value looks roughly one thousand times too large, it is almost certainly milliseconds — divide by 1000 before converting.

How to Use the Timestamp Converter

1. Paste a Unix timestamp such as 1722758400 into the input field.
2. Select the correct unit — seconds or milliseconds — if the tool asks, or let it auto-detect.
3. Read the UTC date, your local timezone date, and the ISO 8601 representation.
4. To go the other way, enter a date like 2024-08-04 00:00:00 and copy the resulting timestamp.
5. Use the relative time display, such as "3 days ago," to sanity-check recent log entries at a glance.

Real Example: Input and Output

Debugging a failed login at 6:45 p.m. local time is faster when the raw log value converts to a readable moment.

Tips for Best Results

• Detect the unit first — an 11-digit value is seconds; a 13-digit value is milliseconds; divide by 1000 before converting the latter.
• Prefer UTC for storage — store timestamps in UTC and convert to local time only for display to avoid timezone drift.
• Beware of negative timestamps — values before 1970 are valid but unusual; a negative number usually signals corrupt data.
• Use ISO 8601 for APIs — 2024-08-04T18:45:00Z is unambiguous across systems, unlike raw epoch integers.
• Round fractional seconds — Python's time.time() includes microseconds; truncate or round before comparing two values.

When to Use This Tool

• Reading logs — convert opaque integers in log lines into the exact moments events happened.
• API debugging — verify that an expires_at field in a token payload still lies in the future.
• Database debugging — inspect created_at columns stored as integers without writing a query.
• Writing tests — generate a fixed epoch value for a specific date so assertions are deterministic.

Frequently Asked Questions