Dhaka Time Zone: Bangladesh Standard Time (BST) and UTC+6
Dhaka, the capital of Bangladesh, runs on Bangladesh Standard Time (BST) at UTC+6 — six hours ahead of Coordinated Universal Time. The IANA timezone identifier is Asia/Dhaka, and it covers the whole country: Chittagong, Khulna, Sylhet and every other Bangladeshi city keep the same time as Dhaka. One caution about the abbreviation: in a South Asian context BST means Bangladesh Standard Time, not British Summer Time — the two are completely different offsets, so always check which one a schedule means.
Bangladesh does not observe daylight saving time. The country made a brief experiment with DST during the 2009 electricity crisis, moving clocks forward an hour for part of the year, but the change proved unpopular and was abandoned; clocks have stayed fixed at UTC+6 ever since. That means any seasonal change in your offset to Dhaka comes from clock changes abroad: London is 6 hours behind Dhaka on GMT and 5 hours behind during British Summer Time, while New York is 11 hours behind during Eastern Standard Time and 10 hours behind during Eastern Daylight Time.
Dhaka's neighbours make South Asia one of the most fragmented timezone regions in the world. India (IST, UTC+5:30) is 30 minutes behind Dhaka — when it is noon in Kolkata, barely 250 kilometres away, it is 12:30 PM in Dhaka. Nepal (NPT, UTC+5:45) is 15 minutes behind Dhaka, and Myanmar (MMT, UTC+6:30) is 30 minutes ahead. Crossing the region from Delhi to Yangon means adjusting your watch three times, never by a whole hour. Bangladesh itself sits on a clean whole-hour offset, which makes Dhaka comparatively easy to schedule against.
Getting Dhaka's time right matters to a surprising share of world commerce, because Bangladesh is the world's second-largest garment exporter after China. The ready-made garment industry concentrated in and around Dhaka supplies major American and European brands, so sourcing teams in New York, London and Amsterdam coordinate daily with factories and buying houses on Dhaka time. Note also that the working week in Bangladesh runs Sunday through Thursday, with the weekend on Friday and Saturday — a Friday-morning email from Europe will not be read until the following Sunday in Dhaka.
For live calls, Europe has the friendliest window: 9:00–11:00 AM in London is mid-afternoon in Dhaka. With the US East Coast, the near-opposite clock means calls land in Dhaka's evening — 8:00 AM in New York is 7:00 PM in Dhaka during winter — while East Asia lines up well, with Singapore and Hong Kong just 2 hours ahead of Dhaka.