HST to JST Converter

It takes three quick steps:

1. Click the HST field on the left and pick the time you want to convert.
2. The matching JST time updates on the right automatically — there’s no button to press.
3. Need a different day? Click the date field and the result follows, rolling over if it crosses midnight.

JST is 19 hours ahead of HST. In everyday terms, once you know the time on one side you just add 19 hours to get the other — so a call between Honolulu and Tokyo is always 19 hours apart.

Right now the time in Japan Standard Time (JST) is Tuesday, June 30, 2026 · 2:53:57 AM. It ticks every second, so you’re always looking at the live JST clock.

And in Hawaii Standard Time (HST), it’s currently Monday, June 29, 2026 · 7:53:57 AM. Compare the two and the 19 hours gap is easy to see.

For example, a 9:00 AM HST meeting takes place at 4:00 AM JST (+1 day). The trick is to aim for a slot that lands inside normal working hours on both sides. Once you’ve found a time, hit Share on the converter to copy a link with the time built in — easy to send to a colleague. Juggling three or more zones? The meeting planner highlights the hours that overlap for everyone.

The labels HST and JST are fixed offsets, so the result on this page is always exact. Neither side changes its clocks for daylight saving, so the difference you see here is the same in summer and winter.

We don’t guess. HST and JST times are worked out from the official IANA time zone database, the trusted standard that operating systems use worldwide. Because daylight-saving rules and regional offsets do change over time, we track those updates rather than relying on a fixed number — which is exactly where many converters slip up.