Nepal, Iran, and Other Fractional Offsets: What They Mean for Your Calendar

Most time zones sit on whole-hour offsets. A handful don’t, and those fractional offsets cause a specific problem: people round them. A contact in Kathmandu told “the call is at 3pm London time” does the mental math and lands on “8-something PM.” They often drop the 45 minutes.

The fractional zones that come up in practice

India (IST) — UTC+5:30 The one most people encounter. The half-hour means overlap windows with the US and Europe never fall on round hours. A 9am New York call is 7:30pm IST, not 7pm or 8pm. See the India scheduling guide for more.

Nepal (NPT) — UTC+5:45 The only 45-minute offset in regular use — Nepal set it 15 minutes ahead of India as a deliberate differentiation. A 9am London call lands at 2:45pm in Kathmandu. No DST.

Iran (IRST/IRDT) — UTC+3:30 / UTC+4:30 Fractional offset and DST. Iran shifts from UTC+3:30 in winter to UTC+4:30 in summer. Iranian DST transitions don’t align with European or US dates, so there are actually four different offset values relative to any fixed-offset zone across the year. Check the current offset before scheduling.

Newfoundland (NST/NDT) — UTC−3:30 / UTC−2:30 Newfoundland is 30 minutes ahead of Halifax and 3.5 hours ahead of Toronto in winter. It also observes DST, so the same compounding problem as Iran. A contact in St. John’s is genuinely in a different class of scheduling complexity than the rest of Canada.

Myanmar (MMT) — UTC+6:30 and Afghanistan (AFT) — UTC+4:30: half-hour offsets, no DST.

Australia’s Northern Territory and South Australia: UTC+9:30. Lord Howe Island uses a 30-minute DST shift, making it UTC+10:30 in winter and UTC+11 in summer — the only zone with a 30-minute DST offset.

What to do about it

State the time in UTC alongside the specific local time for the fractional zone contact:

Call at 14:00 UTC (9am New York / 7:30pm IST / 7:45pm NPT)

Listing their specific city time removes the conversion burden and catches rounding errors before they become no-shows. Don’t leave a fractional-zone contact to do the math themselves.

Use meetwhen with the correct IANA identifier — Asia/Kolkata, Asia/Kathmandu, Asia/Tehran, America/St_Johns — and the tool handles the fractional offsets correctly without rounding.