A timestamp converter translates between Unix epoch time (seconds since 1 January 1970) and human-readable date formats. Developers encounter timestamps daily — in API responses, database records, log files, JWT tokens, and server configs.
This guide explains what Unix timestamps are, how to convert between formats, timezone pitfalls, millisecond vs second timestamps, and practical use cases with code examples.
Convert Timestamps Instantly
Paste any Unix timestamp or date and convert between seconds, milliseconds, ISO 8601, and human-readable formats. Timezone-aware.
What Is a Unix Timestamp (Epoch Time)?
A Unix timestamp is the number of seconds elapsed since 00:00:00 UTC on 1 January 1970 (the "Unix epoch"). It is a single integer that represents an exact moment in time, independent of timezone.
| Timestamp | Date (UTC) | Date (IST) |
|---|---|---|
| 0 | 1 Jan 1970 00:00:00 | 1 Jan 1970 05:30:00 |
| 1000000000 | 9 Sep 2001 01:46:40 | 9 Sep 2001 07:16:40 |
| 1700000000 | 14 Nov 2023 22:13:20 | 15 Nov 2023 03:43:20 |
| 1775692800 | 8 Apr 2026 00:00:00 | 8 Apr 2026 05:30:00 |
| 2000000000 | 18 May 2033 03:33:20 | 18 May 2033 09:03:20 |
Unix was developed in the late 1960s at Bell Labs. The designers chose 1 January 1970 as a convenient, round starting point. All modern operating systems, programming languages, and databases use this as the standard epoch.
Seconds vs Milliseconds: How to Tell the Difference
Some systems use seconds (10 digits), others use milliseconds (13 digits). Getting this wrong is one of the most common timestamp bugs.
| Format | Digits | Example (8 Apr 2026) | Used By |
|---|---|---|---|
| Seconds | 10 | 1775692800 | Unix/Linux, PHP, Python, Ruby |
| Milliseconds | 13 | 1775692800000 | JavaScript, Java, Elasticsearch |
| Microseconds | 16 | 1775692800000000 | PostgreSQL, some APIs |
| Nanoseconds | 19 | 1775692800000000000 | Go, InfluxDB |
If the number has 10 digits → seconds. 13 digits → milliseconds. If you use milliseconds where seconds are expected, your date will be in the year 58,000+. If you use seconds where milliseconds are expected, your date will be in January 1970.
ISO 8601: The International Date Standard
ISO 8601 is the international standard for date/time representation. It eliminates ambiguity across cultures and systems.
Format Variations
| Format | Example | Notes |
|---|---|---|
| Date only | 2026-04-08 | YYYY-MM-DD (no ambiguity) |
| Date + time (UTC) | 2026-04-08T00:00:00Z | Z = Zulu = UTC |
| Date + time (offset) | 2026-04-08T05:30:00+05:30 | IST = UTC+5:30 |
| Date + time (ms) | 2026-04-08T00:00:00.000Z | Millisecond precision |
| Week format | 2026-W15-3 | Week 15, Wednesday |
Store timestamps in UTC (with Z or +00:00) in your database. Convert to local timezone only for display. This prevents timezone bugs when users are in different regions or when daylight saving changes occur.
Timezone Handling: The IST Trap and Other Pitfalls
India Standard Time (IST) = UTC+5:30
India uses a single timezone (UTC+5:30) with no daylight saving. This +5:30 offset is unusual (most offsets are whole hours) and causes bugs in systems that assume hourly offsets.
Common Timezone Bugs
- Midnight crossing — A record created at 11 PM UTC on April 7 is actually April 8 in IST. Filtering by date in the wrong timezone gives wrong results.
- "IST" is ambiguous — IST can mean India Standard Time (+5:30), Irish Standard Time (+1:00), or Israel Standard Time (+2:00). Always use the IANA timezone ID:
Asia/Kolkata. - JavaScript Date gotcha —
new Date("2026-04-08")is parsed as UTC midnight, butnew Date("2026-04-08T00:00:00")may be parsed as local time depending on the browser. - Nepal is UTC+5:45 — Yes, Nepal has a 15-minute offset from India. Systems that round to 30-minute offsets will be wrong for Nepal.
Timestamp Conversion Code Examples
JavaScript
// Current timestamp (seconds)
Math.floor(Date.now() / 1000);
// Timestamp to date
new Date(1775692800 * 1000).toISOString();
// "2026-04-08T00:00:00.000Z"
// Date to timestamp
new Date("2026-04-08").getTime() / 1000;
// 1775692800Python
import datetime
# Timestamp to date
datetime.datetime.utcfromtimestamp(1775692800)
# datetime(2026, 4, 8, 0, 0)
# Date to timestamp
int(datetime.datetime(2026, 4, 8).timestamp())
# 1775692800SQL (MySQL)
-- Timestamp to date
SELECT FROM_UNIXTIME(1775692800);
-- '2026-04-08 00:00:00'
-- Date to timestamp
SELECT UNIX_TIMESTAMP('2026-04-08');
-- 1775692800The Year 2038 Problem
32-bit signed integers can store a maximum value of 2,147,483,647, which corresponds to 19 January 2038 03:14:07 UTC. After this, 32-bit Unix timestamps overflow and wrap to negative numbers (appearing as December 1901).
Who Is Affected?
- Embedded systems (IoT devices, medical equipment, ATMs)
- Legacy databases using 32-bit int for timestamps
- Older PHP versions (before 64-bit support)
- 32-bit Linux systems
The Fix
Use 64-bit integers for timestamps. Modern systems (64-bit Linux, modern databases, JavaScript, Python 3) are already safe — 64-bit timestamps last until the year 292 billion.
The maximum 64-bit timestamp (9,223,372,036,854,775,807) corresponds to approximately 292 billion years in the future — well past the heat death of the universe.
How to Use the Tool (Step by Step)
- 1
Open the Timestamp Converter
Navigate to the tool on ToolsArena — no signup needed.
- 2
Enter a Timestamp or Date
Paste a Unix timestamp (seconds or milliseconds) or enter a human-readable date.
- 3
View Conversion
See the converted result in all formats: Unix seconds, milliseconds, ISO 8601, and local time.
- 4
Copy Result
Copy the converted timestamp or date in your preferred format.
Frequently Asked Questions
What is a Unix timestamp?+−
A Unix timestamp is the number of seconds that have elapsed since 00:00:00 UTC on 1 January 1970 (the Unix epoch). It is a single integer that represents an exact moment in time, used universally in computing for storing and comparing dates.
How do I tell if a timestamp is in seconds or milliseconds?+−
Count the digits: 10 digits = seconds (Unix standard), 13 digits = milliseconds (JavaScript/Java). If your converted date shows year 58,000+, you are treating milliseconds as seconds. If it shows 1970, you are treating seconds as milliseconds.
What is ISO 8601 format?+−
ISO 8601 is the international standard for date/time: YYYY-MM-DDTHH:MM:SSZ. The T separates date and time. Z means UTC. +05:30 means IST offset. It eliminates ambiguity between DD/MM and MM/DD formats used in different countries.
What is the current Unix timestamp?+−
The current Unix timestamp changes every second. As of 8 April 2026, it is approximately 1,775,692,800. Use the converter tool to see the exact current timestamp in real-time.
What is the Year 2038 problem?+−
32-bit signed integers overflow on 19 January 2038 at 03:14:07 UTC. Systems using 32-bit timestamps will malfunction. The fix is using 64-bit integers, which modern systems already support.
How do I handle timezones with timestamps?+−
Store all timestamps in UTC. Convert to local timezone only for display. For India, IST = UTC+5:30. Use IANA timezone IDs (Asia/Kolkata, not "IST") to avoid ambiguity. Never store local times without timezone offset.
What timezone does India use?+−
India uses IST (India Standard Time) = UTC+5:30 across the entire country with no daylight saving time changes. The IANA timezone ID is Asia/Kolkata. Nepal uses UTC+5:45.
Is this tool free and private?+−
Yes. The converter runs entirely in your browser. No timestamps or dates are sent to any server.
Convert Timestamps Instantly
Paste any Unix timestamp or date and convert between seconds, milliseconds, ISO 8601, and human-readable formats. Timezone-aware.
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