Three tools for the time questions that come up in a working day: what a Unix timestamp from a log actually means, what hour a meeting lands on for everyone invited, and how many working days sit between two dates once weekends and public holidays are taken out. All three run in your browser against your own machine's zone data.
- 01
Read a timestamp out of a log
Paste the number as it appears. The digit count decides whether it is seconds or milliseconds, and the result is shown in UTC, ISO 8601, RFC 3339, and your local time at once — with each field copyable.
- 02
Find an hour that works
Add the cities the attendees are in and read the overlap rail: the band where every location is still inside working hours, rather than three clocks you have to compare in your head.
- 03
Quote a realistic delivery date
Count the business days between today and the deadline, or add a number of working days to a start date, with the right country's public holidays excluded so the date survives contact with a calendar.
- 04
Share the exact question
Every setting travels in the link, so the timestamp, the set of cities, or the date range reopens for whoever you send it to, with no screenshot and no explanation needed.
Seconds or milliseconds, decided for you
A ten-digit number is seconds and a thirteen-digit number is milliseconds. The converter detects which you pasted instead of asking, so a value copied out of a log or a database column just works.
Overlap, not just conversion
The zone converter draws the working-hours band that every selected location shares. Answering 'when can we all meet' is a different question from 'what time is it there', and the rail answers the one you actually have.
DST handled by the platform
Offsets come from the IANA database in your browser, so a date in a different daylight-saving period converts correctly rather than being shifted by today's offset.
Holidays, not just weekends
Business day counts can exclude US or UK public holidays as well as weekends, and the counting convention is stated on screen — inclusive of both ends, with the calendar span shown separately.
Copy-ready in every notation
ISO 8601, RFC 3339, UTC, local, and raw epoch values sit side by side, each with its own copy button, so the format your API or database wants is one click away.
Local and free
No account, no server round trip, and no rate limit. The tools keep working with the network disconnected.
What is a Unix timestamp?
The number of seconds since 1 January 1970 UTC, ignoring leap seconds. Many systems use milliseconds instead, which is why the same instant can appear as 1735689600 or 1735689600000 — both are 1 January 2025 at midnight UTC.
How do I tell seconds from milliseconds?
By length. For dates around now, a seconds value has ten digits and a milliseconds value has thirteen. The converter uses that to pick a unit automatically, and shows which one it chose so you can override it if a legacy system uses something else.
How many working days are between two dates?
Count the days in the span, drop the weekends, then drop any public holidays that fall on a weekday. From 1 September to 31 December 2026 that is 121 calendar days and 88 weekdays before holidays are removed — the calculator does the subtraction for the country you select.
Does the time zone converter handle daylight saving?
Yes. Conversions use the IANA time zone database through your browser's own internationalisation support, so a meeting in March converts with March's offset rather than today's — including for the weeks when two regions have switched and one has not.
Which time zone is used for the results?
UTC is always shown, alongside your device's local zone and any cities you add. Nothing is inferred from your IP address, because no request is made in the first place.
Can I share a converted time?
Yes. The timestamp, the selected cities, and the date range are all encoded in the URL, so the link reopens exactly what you were looking at.