IST vs KST time zone comparison

How IST and KST compare

India Standard Time (IST) sits at UTC+05:30 today, while Korea Standard Time (KST) is at UTC+09:00. The current gap is 3 hours, with IST behind KST. In practical terms, if your morning starts at 9 AM in Delhi, your counterpart in Seoul is seeing 12:30 on their own watch at that exact moment.

IST is the working clock for Delhi, Mumbai and Kolkata. IST is ambiguous: India Standard Time, Irish Standard Time, and Israel Standard Time all share the abbreviation. We default to India (largest population). For Ireland use Dublin or WET, for Israel use Asia/Jerusalem. KST covers Seoul, Busan and Incheon. 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 IST nor KST 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. IST and KST differ by 3 hours, which is too small for a clean handoff. Pair this with a third zone for genuine 24-hour coverage.