How to convert Unix timestamps, timezones and ages
These time tools cover the date conversions developers do every day. The Epoch tab converts a Unix timestamp to a human-readable date and back, with a live clock showing the current epoch time. The Timezone tab converts a date and time from one IANA timezone to another. The Age tab calculates an exact age in years, months and days, along with the ISO week and day of the year for the birth date.
All conversions use your browser's built-in Intl timezone database, so they work offline and nothing is sent anywhere.
How to convert a Unix timestamp
- Paste a timestamp into the epoch field — for example
1791500000. The tool shows the date in UTC (ISO 8601) and in your local time. - To go the other way, enter an ISO date such as
2026-10-08T22:53:20Zto get the epoch value. - Click Use current timestamp to fill in the current time.
| Timestamp | Unit | UTC date |
|---|---|---|
0 | seconds | 1970-01-01 00:00:00 |
1791500000 | seconds | 2026-10-08 22:53:20 |
1791500000000 | milliseconds | 2026-10-08 22:53:20 |
2147483647 | seconds | 2038-01-19 03:14:07 (32-bit limit) |
Seconds or milliseconds?
For present-day dates, a 10-digit timestamp is in seconds (Unix tools, most APIs, JWT exp claims) and a 13-digit one is in milliseconds (JavaScript's Date.now(), Java's currentTimeMillis()). If a conversion lands in January 1970, you passed seconds where milliseconds were expected; if it lands tens of thousands of years in the future, it's the opposite.
// JavaScript
Math.floor(Date.now() / 1000) // current time in seconds
new Date(1791500000 * 1000) // seconds → Date
# Python
import time; int(time.time())
# Shell
date +%sConverting between timezones
Choose a source and a target timezone from the full IANA list (Asia/Dhaka, Europe/London, America/New_York…) and enter a date and time. The conversion accounts for daylight saving time on that specific date, which a fixed offset like "UTC−5" cannot. Use it to schedule a meeting across offices, read a log timestamp from a server in another region, or check what a cron schedule in UTC means locally.
Rule of thumb: store and transmit times in UTC, and convert to a local timezone only when displaying them to a person.
Common pitfalls
- Dates without a timezone.
2026-10-09T09:00(noZor offset) is interpreted in the reader's local zone. Always includeZor an offset like+06:00. - DST gaps and overlaps. In zones with daylight saving, some local times happen twice a year and some never happen. Scheduling in UTC avoids both.
- The 2038 problem. Signed 32-bit timestamps overflow at
2147483647(19 January 2038). Use 64-bit integers (BIGINT) for stored timestamps. - Leap seconds are not counted in Unix time, so every day is exactly 86,400 seconds. For almost all application code this doesn't matter.
More detail, including SQL conversions, is in Unix timestamps explained. For date arithmetic like "90 days from today" or business days between two dates, use the date calculator.
Frequently asked questions
What is a Unix timestamp?
The number of seconds since 00:00:00 UTC on 1 January 1970 (the Unix epoch), not counting leap seconds. It identifies an instant independent of any timezone.
What is the current Unix timestamp?
The Epoch tab shows it live, updating every second. In code, use Math.floor(Date.now() / 1000) in JavaScript or date +%s in a shell.
Does the timezone converter handle daylight saving time?
Yes. It uses the IANA timezone database built into your browser, which includes historical and future DST rules for each zone.
How is age calculated?
As complete years, then remaining months, then remaining days between the birth date and today, the way people normally state an age. It also shows the ISO week number and day of the year for the birth date.