UTC Converter
Convert a datetime between UTC and any IANA timezone. Offset follows that zone at the chosen instant, including DST.
Tool input stays in your browserDid you know · Systems
Docker containers share the host kernel, which is why they start in milliseconds rather than seconds.
Convert
you editChange either calendar — both sides always describe the same instant.
Results
read onlyClick any tile to copy it.
Right now in UTC01/06/2024, 12:00:00|UTC2024-06-01T12:00:00.000Z
Local digits versus UTC digits
A datetime-local picker has no timezone. Search an IANA name or an offset such as +5:30 or +4:00. The default is this browser. Changing the zone keeps the same instant and reprints the local calendar. The UTC field reads the same shape as Date.UTC— year, month, day, hour, minute, second as Coordinated Universal Time. Editing either side keeps one instant; the other calendar and the ISO string update together.
ISO 8601 and HTTP dates
APIs almost always want 2024-06-01T12:00:00.000Z. HTTP Date headers use RFC 1123 (GMT). Paste either into the text field and Apply. Unix seconds are the same instant for logs and JWT exp. For epoch-first workflows use the Unix timestamp converter.
DST and offset
The offset is computed in the selected timezone at the chosen instant, not “standard time” for the year. Europe/London in summer is UTC+01:00; the same clock in winter is UTC+00:00. A time that does not exist (spring-forward gap) is rejected. Conversion never sends the datetime to a server. The last chosen zone is stored in this browser only.
UTC converter FAQ
UTC to local, local to UTC, ISO 8601 Z, RFC 1123, and timezone offset.
What is a UTC converter?
A UTC converter turns a local wall-clock time into Coordinated Universal Time, and the reverse. This page keeps one instant: edit Local or UTC, then copy ISO 8601 (Z), RFC 1123, the zone offset, or Unix seconds. Everything runs in the browser.
How do I convert local time to UTC?
Set the Local picker to the wall-clock time in the selected timezone. The UTC picker, ISO string, and offset update immediately. DST is applied at that instant. Switch the timezone menu to convert the same instant for another city. Use 12-hour or 24-hour for the calendar tiles; ISO 8601 stays 24-hour.
How do I convert UTC to local time?
Set the UTC picker (those digits are treated as Z, not as local). You can also paste an ISO-8601 string ending in Z or an RFC 1123 GMT date and choose Apply.
What does the offset mean?
Offset is the selected timezone’s difference from UTC at the chosen instant, written UTC±HH:MM. It can change across DST. The IANA name (for example Europe/London) is shown in the timezone menu and remembered in this browser.
Can I pick a timezone other than this computer?
Yes. Search the timezone field for an IANA name (Kolkata) or an offset (+5:30, UTC+4, +0400). Chips under the field jump to common offsets. Use browser zone restores this device. Changing the zone does not change the UTC instant; it only reprints local time.
Is the UTC converter private?
Yes. Conversion uses the JavaScript Date API in this tab. Meeting times and log stamps are not uploaded. The chosen timezone is stored only in this browser.