HST vs SGT time zone comparison

How HST and SGT compare

Hawaii Standard Time (HST) sits at UTC-10:00 today, while Singapore Time (SGT) is at UTC+08:00. The current gap is 18 hours, with HST behind SGT. In practical terms, if your morning starts at 9 AM in Honolulu, your counterpart in Singapore is seeing 03:00 on their own watch at that exact moment.

HST is the working clock for Honolulu. SGT covers Singapore. If your team is split between these two regions, the table above is the quickest way to spot the daily overlap window without doing the offset arithmetic in your head.

Neither HST nor SGT observes daylight saving in the modern era, which is unusual and convenient: the gap between the two zones stays the same in January and in July. You can quote the offset once and forget about it.

Common scheduling traps are easy to avoid here. Pick a wall-clock time on one side, read the matching wall-clock on the other from the table, and write both into the calendar invite, never just the difference. If the meeting falls in the week of a DST changeover and one of these zones shifts, the absolute clock will drift by an hour from what the recipient expects. The table is computed for today's date, so for a future meeting open the converter linked above and pick the exact date.

One last note for asynchronous teams: business-hour overlap is the wrong metric for handoff workflows. If you operate on a follow-the-sun model, you actually want zero overlap, with one team logging off as the other starts. HST and SGT differ by 18 hours, which gives you partial coverage. Add a zone in between if you want full 24-hour rotation.