Timestamp Converter — Unix Time to Date & Date to Timestamp

Unix timestamps are everywhere, and they're unreadable without help

1718000000. If you've spent any time in a database, an API response, a log file, or a server config, you've seen numbers like this. They're Unix timestamps — the number of seconds (or milliseconds) elapsed since January 1, 1970, 00:00:00 UTC. They're precise, compact, and completely unreadable to humans without conversion.

A timestamp converter translates between Unix timestamps and human-readable dates instantly — in both directions. Given a timestamp, it tells you the date and time. Given a date, it gives you the timestamp.

What Is a Unix Timestamp?

The Unix epoch — the starting point of Unix time — is January 1, 1970, 00:00:00 UTC. A Unix timestamp is the number of seconds since that moment.

• 0 = 1970-01-01 00:00:00 UTC
• 1000000000 = September 9, 2001, 01:46:40 UTC
• 1718000000 = June 10, 2024, 10:13:20 UTC

Some systems use millisecond timestamps (multiply seconds by 1,000):

• 1718000000000 = same moment, in milliseconds

And some use microseconds (multiply by 1,000,000) or nanoseconds (multiply by 1,000,000,000) — common in high-precision logging and profiling.

How to Use the Timestamp Converter on sadiqbd.com

Unix timestamp to human date:

1. Paste the timestamp (seconds or milliseconds).
2. The converter detects the format and shows the date and time in UTC and your local timezone.

Human date to Unix timestamp:

1. Enter or select the date and time.
2. Specify the timezone (or leave as UTC/local).
3. The converter outputs the Unix timestamp in seconds and milliseconds.

Current timestamp: Most timestamp converters also show the current Unix timestamp, live — useful for sanity-checking "what is right now as a timestamp."

Real-World Examples

Reading a database record

A database row shows:

created_at: 1715200000
updated_at: 1717900000

Converting:

• 1715200000 → 2024-05-08 21:46:40 UTC
• 1717900000 → 2024-06-09 05:06:40 UTC

The record was created in early May and last updated in early June. Immediately readable.

Debugging an API response

An API returns:

{
  "expires_at": 1718003600,
  "issued_at": 1718000000
}

• issued_at → 2024-06-10 10:13:20 UTC
• expires_at → 2024-06-10 11:13:20 UTC

Token lifetime: exactly 1 hour. Current time is 1718010000 → 2024-06-10 12:16:40 UTC. The token expired 75 minutes ago — that's why the request is failing.

Setting a cookie expiry

You want a cookie to expire in 30 days. Current timestamp: 1718000000.

30 days × 24 hours × 3600 seconds = 2,592,000 seconds

Expiry timestamp: 1718000000 + 2592000 = 1720592000

Converting to verify: 1720592000 → 2024-07-10 10:13:20 UTC ✓

Checking a log entry time

A server log shows:

[1717998432.847] ERROR Connection timeout to upstream

1717998432 → 2024-06-10 09:47:12 UTC (plus 847 milliseconds)

Cross-referencing with another log in a different format (ISO 8601: 2024-06-10T09:47:13Z) confirms both logs describe the same second — the issue is consistent across services.

Calculating time differences

Two events:

• Event A: timestamp 1718000000
• Event B: timestamp 1718003742

Difference: 3,742 seconds = 62 minutes and 22 seconds.

This kind of calculation — how long between two events — comes up constantly in performance profiling, SLA monitoring, and debugging.

Seconds vs. Milliseconds: Telling Them Apart

A common source of confusion is whether a timestamp is in seconds or milliseconds. The heuristic:

• 10-digit timestamp (1,000,000,000 – 9,999,999,999): seconds — covers years ~2001 to ~2286
• 13-digit timestamp (1,000,000,000,000+): milliseconds — covers the same range multiplied by 1,000

1718000000 → seconds (10 digits) → June 2024 1718000000000 → milliseconds (13 digits) → also June 2024

If you get a wildly wrong date (year 1970, year 55000, etc.), you've probably got the seconds/milliseconds distinction backwards. The timestamp converter typically auto-detects based on magnitude.

Timezones and Unix Timestamps

Unix timestamps are always in UTC — they have no timezone. The same timestamp represents a different local time depending on where you are.

1718000000 in UTC = 10:13:20 UTC In Dhaka (UTC+6) = 16:13:20 In New York (UTC-5) = 05:13:20

This is a common source of bugs: storing a timestamp is fine, but displaying it requires knowing the viewer's timezone. The converter shows you the UTC time and converts to your local time automatically.

Tips for Working With Timestamps

Always store timestamps in UTC. Dates stored in local time are ambiguous — they change meaning when servers move or users are in different timezones. UTC timestamps are unambiguous.

Use milliseconds for anything event-driven. Seconds-precision is fine for expiry dates and coarse-grained scheduling. For event logs, performance metrics, and anything where sub-second ordering matters, use milliseconds.

Be explicit about format in APIs. If your API returns timestamps, document whether they're seconds or milliseconds. Mixing both in different fields is a guaranteed source of client-side bugs.

Use ISO 8601 for human-readable dates in APIs. 2024-06-10T10:13:20Z is unambiguous, sortable as a string, and parseable by every modern language without a library. Use Unix timestamps for arithmetic; ISO 8601 for display.

Frequently Asked Questions

Why does Unix time start at 1970? January 1, 1970 was chosen as a convenient epoch when Unix was designed in the late 1960s/early 1970s. The choice was largely arbitrary — it needed to be recent enough to represent modern times with reasonable-sized numbers.

What is the "Year 2038 problem"? Unix timestamps stored as 32-bit signed integers overflow on January 19, 2038, at 03:14:08 UTC (2³¹ − 1 seconds after the epoch). Systems still using 32-bit time_t will wrap around to 1970. Modern 64-bit systems are unaffected — a 64-bit timestamp won't overflow for approximately 292 billion years.

What's the difference between a Unix timestamp and an ISO 8601 date? A Unix timestamp is an integer (seconds/ms since epoch). ISO 8601 is a formatted string (2024-06-10T10:13:20Z). Both represent the same moment; the format differs. Timestamps are better for arithmetic and storage; ISO 8601 is better for display and interchange.

Can I convert timestamps for dates before 1970? Yes — negative Unix timestamps represent dates before the epoch. -86400 is December 31, 1969, 00:00:00 UTC.

Is the timestamp converter free? Yes — completely free, no sign-up needed.

Unix timestamps are the lingua franca of time in software — databases, APIs, logs, and configuration files all use them. The converter makes the translation to and from human-readable dates immediate, so you spend less time manually calculating and more time on the actual work.

Try the Timestamp Converter free at sadiqbd.com — convert Unix timestamps to dates and back instantly.