JST ↔ SGT Time Converter

Singapore Standard Time (SGT) is 1h behind Japan Standard Time (JST). For example, when it is 9:00 AM in JST, it is 8:00 AM in SGT. Japan Standard Time runs at UTC+9 while Singapore Standard Time runs at UTC+8. Always confirm with the live converter above since Daylight Saving Time can shift this offset during certain months of the year.

The quickest way is to use the live bidirectional converter at the top of this page — type any time into the JST field and the SGT result appears instantly. For a manual calculation, subtract 1h to the JST time. So noon (12:00 PM) in JST becomes 11:00 AM in SGT. If the result goes past midnight, adjust by ±24 hours and note the day change. The 24-hour table further down this page also covers every hour of the day at a glance.

Singapore Standard Time (SGT) is 1h behind Japan Standard Time (JST). In practical terms, clocks in SGT show an earlier time than clocks in JST. The UTC reference points are UTC+9 for JST and UTC+8 for SGT, giving a net raw difference of 1h behind. Remember this raw figure may shift by ±1h when either zone enters or exits Daylight Saving Time.

Type a time into the SGT field in the bidirectional converter above — it works equally in both directions. Manually, do the reverse: add 1h to the SGT time to get JST. You can also visit the dedicated SGT to JST converter page, which has its own live clocks, full table, and meeting planner for the reverse direction.

Because SGT is 1h behind JST, the ideal scheduling window is wherever both zones overlap within 8:00 AM–6:00 PM local time. Check the meeting hours table above for exact slot recommendations. As a general rule, aim for 8:00 AM–11:00 AM JST time — this typically keeps the SGT side within a reasonable morning or afternoon window. Avoid scheduling calls that land before 7:00 AM or after 8:00 PM in either timezone, as attendance and productivity tend to suffer.

Japan Standard Time (JST) does not observe Daylight Saving Time and stays at a fixed UTC offset year-round. If you are scheduling meetings or deadlines that span a DST transition, always recheck the exact offset using the live converter on this page rather than relying on a fixed-offset table, which will be off by one hour during those periods.

Singapore Standard Time (SGT) does not observe Daylight Saving Time, staying at a fixed offset. The live clocks and bidirectional converter on this page use the IANA timezone database and update automatically the moment DST begins or ends, so you never need to manually account for the seasonal shift.

Japan Standard Time (JST) at UTC+9 covers the following major cities and regions: Tokyo, Osaka, Kyoto, Yokohama, Nagoya, Sapporo, Fukuoka. Not every locality within a country necessarily follows the same standard time — some regions may use sub-zones or observe different DST rules — so always verify local time when precision matters.

Singapore Standard Time (SGT) at UTC+8 covers the following major cities and regions: Singapore, Kuala Lumpur, Penang, Johor Bahru. As with any timezone, confirm local rules for areas near geographic or political boundaries, where the observed offset can occasionally differ from the standard definition.

Midnight (12:00 AM / 00:00) in JST corresponds to 11:00 PM in SGT — which falls the previous day. This is generally outside normal business hours for both sides. Use the full 24-hour conversion table on this page to quickly look up any other reference time.

Simple formula: SGT = JST – 1h. Example: 3:00 PM JST → 2:00 PM SGT. If the result exceeds 11:59 PM, subtract 24 hours and add one day; if it goes below 12:00 AM, add 24 hours and subtract one day. This fixed formula is accurate when neither zone is in a DST transition — during transitions, rely on the live converter above.

Japan Standard Time (JST) is at UTC+9 and Singapore Standard Time (SGT) is at UTC+8. UTC (Coordinated Universal Time) is the global timekeeping standard against which all timezone offsets are defined. A positive offset like UTC+5 means the local clock is 5 hours ahead of UTC; a negative offset like UTC-5 means it is 5 hours behind. The net difference between UTC+9 and UTC+8 gives the conversion gap of 1h behind used throughout this page.

The live converter uses your browser's built-in Intl.DateTimeFormat API backed by the IANA timezone database (IANA identifiers: Asia/Tokyo for JST, Asia/Singapore for SGT). This automatically applies DST transitions in real time, making the live clocks and converter highly accurate. The static 24-hour table uses fixed offsets and may differ by ±1 hour during DST periods — always prefer the live converter for critical scheduling.

Yes — this page is fully responsive and works on smartphones and tablets. The time input fields, swap button, and live clocks all function on iOS and Android browsers. You can also tap any row in the 24-hour conversion table to instantly load that time into the converter fields above.