JST to HST Converter

It takes three quick steps:

1. Click the JST field on the left and pick the time you want to convert.
2. The matching HST 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.

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

Right now the time in Hawaii Standard Time (HST) is Monday, June 29, 2026 · 7:54:04 AM. It ticks every second, so you’re always looking at the live HST clock.

And in Japan Standard Time (JST), it’s currently Tuesday, June 30, 2026 · 2:54:04 AM. Compare the two and the 19 hours gap is easy to see.

For example, a 9:00 AM JST meeting takes place at 2:00 PM HST (−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 JST and HST 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. JST and HST 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.