JST time
The offset and the abbreviation for Tokyo and Osaka — the same on every date the pinned table covers.
What is the UTC offset of JST time?
It is UTC+09:00 on every date the pinned table covers. This zone has no daylight saving, so one number describes it correctly all year.
Right now
The current reading appears once this page finishes loading.
When do the clocks change?
They do not. The pinned IANA release lists no clock change for this zone at all, so an offset read here holds for any date the table covers.