Unix timestamp converter - epoch time to date (and back)

A Unix timestamp (also called epoch time) is a number that represents a moment in time. Most systems define it as the number of seconds since 1970-01-01 00:00:00 UTC. If you work with logs, APIs, databases, or JWTs, you’ll see it all the time.

This converter turns timestamps into readable dates, and it turns dates back into Unix time in seconds and milliseconds.

If you want the formal definition, see the overview on Unix time.

1. Paste a timestamp or date: Examples: 1700000000, 1700000000000, or 2026-01-10T15:30:00Z.
2. Pick the mode (optional): Keep Auto-detect unless you want to force a direction.
3. Copy the results: You’ll get seconds, milliseconds, UTC, and local time in one output.

• Faster debugging: Convert a value from logs into a date you can reason about.
• Fewer timezone mistakes: See both UTC and your local time in one place.
• Works with seconds or milliseconds: The tool can infer the unit from common formats.

How to spot seconds vs milliseconds

Most systems use one of these two formats:

If your value looks like it’s in the year 1970 or 51382, the unit is usually wrong. Switch the “Timestamp unit” setting and try again.

Use case 1: debugging API logs

Many APIs return created_at or expires_at as epoch values. Paste the value to confirm whether it’s in the past, in the future, or off by a unit (seconds vs milliseconds).

Use case 2: checking token expiration

JWT payloads often include an exp claim in epoch seconds. Decode your token with the JWT Decoder, then paste the exp value here to see the expiration time.

Use case 3: writing cron and scheduling rules

If you’re building a scheduled job, you’ll usually store a timestamp somewhere. Use this converter to sanity-check the time you’re about to ship, then build the schedule with the Cron Builder.

Basic example: seconds timestamp to date

Input:

1700000000

Output (example format):

Unix (seconds): 1700000000
Unix (milliseconds): 1700000000000
UTC: 2023-11-14T22:13:20.000Z
Local: 11/14/2023, 05:13:20 PM EST

Advanced example: milliseconds timestamp to date

Input:

1700000000000

Tip: If you paste a 13-digit value, Auto-detect will usually treat it as milliseconds.

Fractional seconds example

Some systems include sub-second precision in seconds form:

Input:

1700000000.123

The converter will round to the nearest millisecond for display.

Date to timestamp example (ISO 8601)

Input:

2026-01-10T15:30:00Z

Output includes:

• Unix seconds
• Unix milliseconds
• UTC ISO time
• Local time with your timezone name

“My timestamp is off by 1000x”

This is the most common problem. Some systems store timestamps in seconds (10 digits), and others store them in milliseconds (13 digits).

Fix: switch “Timestamp unit” to Seconds or Milliseconds, or keep Auto and paste the raw value you received.

“The time looks right in UTC but wrong locally”

UTC is the source of truth for most logs and APIs. Your local time depends on your device settings and daylight saving time.

Fix: use the UTC line when you need a stable reference, and use the Local line when you need to match what your computer shows.

“My date input won’t parse”

Date parsing can be strict. If you paste a date like 01/10/2026, it can be ambiguous across regions.

Fix: use ISO 8601 whenever you can, like 2026-01-10T15:30:00Z. For details on what JavaScript can parse, see the notes on Date parsing.

“My timestamp is negative”

Negative timestamps represent dates before 1970-01-01 UTC. That’s normal for historical dates. If you didn’t expect it, double-check that you didn’t accidentally paste a duration or an ID field.

• Keep timestamps in UTC in storage: Convert to local time only at the UI edge.
• Normalize units early: When you ingest data, convert everything to milliseconds (or seconds) once, then keep it consistent.
• Pair it with a payload viewer: Decode JWTs with the JWT Decoder, then format related JSON with the JSON Formatter.
• Verify before you ship: Paste the final value you plan to deploy (expiry, schedule start, etc.) and confirm it lands on the intended day and hour in UTC.

• Inspect exp and iat claims with the JWT Decoder.
• Clean up payloads with the JSON Formatter.
• Build schedules using the Cron Builder.
• Decode timestamps embedded in strings with the Base64 Encoder/Decoder.

This timestamp converter runs in your browser. Your input is not uploaded or stored.