Convert JST (Japan Standard Time) to CST (Central Standard Time)

Which CST is this?

CST names more than one zone. This page reads it as Central Standard Time at UTC−6, which is the reading most converters take. There are others: China Standard Time at UTC+8, used in all of mainland China, all year; Cuba Standard Time at UTC−5, used in Cuba in winter.

The letters on a meeting invitation do not say which one is meant. If yours is not Central Standard Time, the answer above is wrong, and not by a little:

Any converter has to pick one of these readings before it can answer, and two of them can pick differently — a page of search results for a CST conversion can show you both answers with neither being wrong. The one to trust is whichever states the zone it means rather than only the letters. Where it matters, ask which country the sender is in.

Best time to schedule a meeting

Standard 9–5 working hours do not overlap at all between JST and CST. Someone has to take an early or late call — or use asynchronous communication instead.

JST to CST conversion table

About JST

Japan Standard Time (JST) is UTC+9. It is used in all of Japan, with no daylight saving.

Japan Standard Time is UTC+9 for the whole country and has had no daylight saving since 1951, when the occupation-era experiment was abandoned. Proposals to reintroduce it, most recently before the 2020 Olympics, have failed each time. The offset is shared with South Korea, so Tokyo and Seoul never differ by even a minute.

About CST

Central Standard Time (CST) is UTC−6. It is used in Chicago, Dallas, Houston and Mexico City in winter.

CST is the most overloaded abbreviation in timekeeping. It means US Central Standard Time at UTC−6, China Standard Time at UTC+8, and Cuba Standard Time at UTC−5 — a fourteen-hour spread between the first two. This page uses the North American meaning. If an abbreviation reached you without a country attached, that is a reason to ask rather than to assume, and it is the strongest single argument for storing an IANA zone name such as America/Chicago instead.

Does this gap change with the seasons?

This gap is seasonal. The abbreviations themselves are fixed offsets, but the region on CST switches to CDT (UTC−5) from March to November. So the 15-hour figure on this page is correct for the part of the year when both places are actually on these abbreviations, and changes by an hour outside it.

JST does not shift, so the whole change comes from one side. A recurring meeting fixed in JST will appear to move by an hour for everyone on the other side, twice a year, without anyone changing anything.

This is the reason scheduling systems store an IANA zone such as Region/City rather than an offset or an abbreviation: the zone knows its own rules and the offset does not.

Frequently asked questions