Batch Timestamp Converter

Paste multiple timestamps (one per line). Auto-detect format. Convert all to Unix, ISO 8601, human-readable, and relative time.

Timestamps (one per line)
Paste timestamps above, one per line.

How to Use the Batch Timestamp Converter

  1. Paste timestamps — one per line. Mix Unix seconds, milliseconds, and ISO 8601 freely.
  2. Click Convert All — or it converts automatically as you type.
  3. Sort the table — click any column header to sort.
  4. Export — click Export CSV to download all rows as a spreadsheet-ready file.

Timestamp Formats Explained

Applications and databases store dates and times in a variety of formats. When debugging logs, analyzing data exports, or integrating systems that use different timestamp conventions, you often need to convert between them quickly. This batch converter handles the most common formats automatically.

Unix Timestamps (Epoch Seconds)

A Unix timestamp counts the number of seconds elapsed since midnight UTC on January 1, 1970 — the "Unix epoch". This is the most universal timestamp format, used natively by POSIX operating systems, C/C++, Python's time.time(), Go's time.Unix(), and many databases. Unix timestamps in seconds are typically 10 digits. For example, 1711094400 is 2024-03-22 12:00:00 UTC.

Unix Milliseconds

Many modern systems use millisecond precision. JavaScript's Date.now() returns milliseconds. Java's System.currentTimeMillis() returns milliseconds. MongoDB's ObjectIDs encode milliseconds. Millisecond timestamps are 13 digits. For example, 1711094400000 is the same moment as 1711094400 seconds, just with three extra zeros.

ISO 8601

ISO 8601 is the international standard for date-time strings. It looks like 2024-03-22T14:30:00Z (UTC), 2024-03-22T14:30:00+05:30 (with offset), or simply 2024-03-22 (date only). This format is unambiguous, sortable as a string, and supported natively by every major programming language and database. REST APIs, JSON payloads, and log files commonly use ISO 8601.

Human-Readable Format

The human-readable column shows the date and time in a clear format like "Friday, March 22, 2024 at 12:00:00 UTC". This is useful for quickly verifying whether a timestamp is correct without mentally converting from epoch numbers.

Relative Time

Relative time shows how long ago or in the future a timestamp is — "3 days ago", "in 2 hours", "just now". This is calculated by comparing the timestamp to the current moment. It is especially useful for log analysis: seeing that a database error occurred "47 minutes ago" is more actionable than seeing a raw epoch number.

Common Use Cases

Batch timestamp conversion is used for: analyzing server logs that contain Unix timestamps, debugging API responses with mixed timestamp formats, processing database exports, comparing event timelines across distributed systems, converting timestamps from one timezone for display to users in another timezone, and verifying that scheduled jobs fired at the correct times.

Timezone Considerations

Unix timestamps are always in UTC by nature — they represent an absolute moment in time. ISO 8601 strings can include a timezone offset. The "Human-readable" and "Relative time" columns in this tool can be shown in either UTC or your local browser timezone — use the timezone selector to switch. For server-side work, UTC is almost always preferred. For user-facing interfaces, local time is more intuitive.

Frequently Asked Questions

A Unix timestamp is the number of seconds (or milliseconds) elapsed since 00:00:00 UTC on January 1, 1970. It is a universal way to represent moments in time as a single integer. Unix seconds are 10 digits; milliseconds are 13 digits.
13-digit numbers are treated as Unix milliseconds. 10-digit numbers as Unix seconds. Strings matching ISO 8601 patterns (containing T, Z, or date separators) are parsed as ISO 8601. Everything else is marked invalid.
ISO 8601 is the international standard for date-time strings. Examples: 2024-03-22T14:30:00Z (UTC), 2024-03-22T14:30:00+05:30 (with offset), 2024-03-22 (date only). Used by most databases, APIs, and languages.
Relative time shows how far in the past or future a timestamp is compared to now — e.g., "3 days ago" or "in 2 hours". It is calculated by subtracting the current time from the timestamp and formatting the difference in human-readable units.
Click the "Export CSV" button. The CSV includes columns for original input, detected format, Unix seconds, Unix milliseconds, ISO 8601, human-readable date, and relative time. It downloads directly to your computer.