Timestamp Converter Online: Convert Unix Timestamps to Human-Readable Dates
Unix timestamps appear everywhere in development — API responses, database records, log files, JWT tokens, and webhook payloads. They're precise, timezone-neutral, and easy to compare. But they're completely unreadable to humans. 1711238400 tells you nothing at a glance.
A timestamp converter online lets you instantly convert between Unix timestamps and human-readable dates without writing any code.
What Is a Unix Timestamp?
A Unix timestamp (also called Unix time or POSIX time) is the number of seconds elapsed since January 1, 1970, 00:00:00 UTC — known as the Unix epoch.
1711238400 → 2024-03-24 00:00:00 UTC
0 → 1970-01-01 00:00:00 UTC
-86400 → 1969-12-31 00:00:00 UTC (negative = before epoch)
Millisecond timestamps (common in JavaScript) are 1000× larger:
1711238400000 → 2024-03-24 00:00:00 UTC (milliseconds)
Try it now: DevPlaybook Timestamp Converter — convert any Unix timestamp to a readable date and vice versa.
Why Timestamps Are Used in Programming
1. Timezone Independence
A timestamp is always UTC. There's no ambiguity about "which timezone" — 1711238400 means the same moment regardless of where the server or client is located.
2. Easy Math
Comparing, sorting, and calculating durations with timestamps is simple arithmetic:
const dayInSeconds = 86400;
const tomorrow = Date.now() / 1000 + dayInSeconds;
const isExpired = expiryTimestamp < Date.now() / 1000;
3. Compact Storage
A timestamp is a single integer. Storing it in a database as BIGINT is more efficient than a DATETIME or TIMESTAMP WITH TIME ZONE string.
4. Universal Compatibility
Every programming language, database, and platform understands Unix timestamps natively.
How to Use an Online Timestamp Converter
- Open DevPlaybook Timestamp Converter
- Paste a timestamp (seconds or milliseconds) into the input
- See the converted date, time, and your local timezone representation
- Or enter a date to get the corresponding Unix timestamp
The tool automatically detects whether you're entering seconds or milliseconds based on the value size.
Converting Timestamps in Code
JavaScript
// Timestamp to date
const ts = 1711238400;
const date = new Date(ts * 1000); // multiply by 1000 for milliseconds
console.log(date.toISOString()); // "2024-03-24T00:00:00.000Z"
console.log(date.toLocaleString()); // local timezone representation
// Date to timestamp
const now = Math.floor(Date.now() / 1000); // seconds
const nowMs = Date.now(); // milliseconds
// Specific date to timestamp
const specific = Math.floor(new Date("2024-03-24").getTime() / 1000);
Python
import datetime
# Timestamp to datetime
ts = 1711238400
dt = datetime.datetime.fromtimestamp(ts, tz=datetime.timezone.utc)
print(dt) # 2024-03-24 00:00:00+00:00
# Datetime to timestamp
from datetime import timezone
now = datetime.datetime.now(timezone.utc)
ts = int(now.timestamp()) # seconds
SQL
-- PostgreSQL: timestamp to readable
SELECT to_timestamp(1711238400);
-- MySQL: timestamp to readable
SELECT FROM_UNIXTIME(1711238400);
-- SQLite: timestamp to readable
SELECT datetime(1711238400, 'unixepoch');
-- Current timestamp
SELECT EXTRACT(EPOCH FROM NOW())::INTEGER; -- PostgreSQL
SELECT UNIX_TIMESTAMP(); -- MySQL
Go
import "time"
ts := int64(1711238400)
t := time.Unix(ts, 0).UTC()
fmt.Println(t.Format(time.RFC3339)) // "2024-03-24T00:00:00Z"
Common Timestamp Mistakes
Milliseconds vs Seconds Confusion
JavaScript uses milliseconds, most other systems use seconds. A 13-digit number is milliseconds; 10-digit is seconds.
// ❌ WRONG — treating milliseconds as seconds
new Date(1711238400); // Results in year 1970!
// ✅ CORRECT
new Date(1711238400 * 1000); // Unix seconds → Date
new Date(1711238400000); // Already milliseconds → Date
Timezone Off-by-One Errors
When converting to local time, always be explicit:
// ❌ Ambiguous — uses local timezone, varies by machine
new Date(ts * 1000).toLocaleDateString();
// ✅ Explicit UTC
new Date(ts * 1000).toISOString();
// ✅ Explicit local with Intl API
new Intl.DateTimeFormat('en-US', { timeZone: 'America/New_York' })
.format(new Date(ts * 1000));
The Year 2038 Problem
32-bit signed integers can only represent timestamps up to January 19, 2038 (timestamp 2147483647). Always use 64-bit integers for timestamps in systems expected to run past 2038.
Timestamp Formats Reference
| Format | Example | Notes |
|---|---|---|
| Unix seconds | 1711238400 |
10 digits, most common |
| Unix milliseconds | 1711238400000 |
13 digits, JavaScript default |
| ISO 8601 | 2024-03-24T00:00:00Z |
Human-readable, timezone explicit |
| RFC 2822 | Sun, 24 Mar 2024 00:00:00 +0000 |
Email headers |
| HTTP date | Sun, 24 Mar 2024 00:00:00 GMT |
Cache-Control, Last-Modified headers |
Frequently Asked Questions
What's the current Unix timestamp?
The current timestamp changes every second. Use DevPlaybook Timestamp Converter to see the live current timestamp, or run date +%s in a terminal.
How do I convert a timestamp to a specific timezone?
Unix timestamps are always UTC. To display them in a specific timezone, convert them in your application layer using Intl.DateTimeFormat (JS), pytz (Python), or time.LoadLocation (Go). The timestamp itself doesn't change — only the display changes.
What timestamp corresponds to "now" in 5 minutes?
Add 300 seconds (5 minutes × 60 seconds) to the current timestamp:
const fiveMinutesFromNow = Math.floor(Date.now() / 1000) + 300;
Why do JWT tokens use Unix timestamps?
JWT exp, iat, and nbf claims use Unix timestamps because they're compact, language-neutral, and timezone-safe — critical for tokens that might be validated by systems in different locations.
Is there a timestamp for "never expires"?
There's no universal standard, but common conventions are using null/undefined in application code, or a far-future timestamp like 9999999999 (year 2286). Avoid 2147483647 (year 2038) for 32-bit systems.
Related Tools
- JSON Formatter — format API responses containing timestamps
- URL Encoder/Decoder — decode timestamps in URL parameters
- Cron Expression Generator — schedule jobs at specific timestamps
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