🇻🇳 Hanoi

Hanoi uses the Muslim World League method (method 3 in our calculator), an 18° Fajr and 17° Isha convention adopted as the practical default by the Al-Noor Mosque, the only mosque in the Vietnamese capital. Vietnam has no nationwide Islamic authority and its Muslim population is concentrated in the Mekong Delta and Ho Chi Minh City rather than in the north, so the small Hanoi community has settled on MWL as a balanced default appropriate for the city's 21°N tropical latitude and consistent with the convention used by most non-Muslim-majority countries in the region. Al-Noor's published schedule, which most worshippers consult by phoning the mosque office or via international apps, follows this method. Visitors arriving with apps set to Muslim World League will see times that match what the mosque announces; those configured for Egyptian or Karachi conventions will see Fajr and Isha shifted by a few minutes, while Dhuhr, Asr and Maghrib remain identical because they depend on the sun's altitude rather than the twilight angle.

Prayer times in Hanoi shift modestly across the year because the city sits at 21°N, near the Tropic of Cancer, so day length varies more noticeably than in fully equatorial Southeast Asian capitals but far less than in mid-latitude cities. In late June, sunrise is around 05:15 and Maghrib around 18:55, producing roughly thirteen and a half hours of daylight; by late December those values shift to a 06:35 sunrise and a 17:25 Maghrib, giving about ten hours fifty minutes. The full Fajr-to-Maghrib swing across the year is therefore about two hours forty minutes, in contrast to the near-flat tropical timetables of Manila, Jakarta or Singapore. The bigger seasonal driver is the northeast monsoon between October and April, which produces persistent low cloud cover and drizzle (the Hanoi crachin) that makes horizon observation impossible. Al-Noor Mosque relies entirely on calculated tables published monthly.

Hanoi hosts a very small Muslim community of perhaps a few thousand people across the wider metropolitan area, made up largely of expatriates from Indonesia, Pakistan, the Arab world and India, alongside a small number of Vietnamese converts and visiting students. The country's main Muslim population is the Cham community in the Mekong Delta and the An Giang and Tay Ninh provinces near the Cambodian border, with a secondary Cham concentration in Ho Chi Minh City; Hanoi's community is correspondingly thin because it lies hundreds of kilometres north of those historical settlement zones. The Al-Noor Mosque in the Old Quarter, founded in 1890 by Indian Muslim merchants and later renovated, is the institutional heart of the capital's Muslim life. Halal restaurants are limited but growing in Hoan Kiem and Tay Ho districts, and Indonesian and Malaysian embassies maintain prayer rooms for staff and visitors.

Friday prayer in Hanoi is held at the Al-Noor Mosque on Hang Luoc Street in the Old Quarter, the only mosque in the Vietnamese capital. Originally built in 1890 by Indian Muslim merchants from the Bombay Presidency who had settled in colonial Indochina, and renovated several times since, the modest building accommodates around two hundred worshippers in its main prayer hall and is the focal point for the entire city's Muslim community. Friday khutbas are typically delivered in English or Arabic to suit the predominantly expatriate congregation, with translation help offered for Vietnamese converts and visitors. Outside Friday, the mosque hosts daily prayers — though attendance for the dawn and night prayers is usually small — and serves as a community centre, occasional halal-information point and the city's most reliable contact for visiting Muslim travellers seeking prayer space. Eid congregations spill onto the surrounding lanes.

Prayer times differ between cities because they are calculated from the apparent position of the sun, which depends on each city's latitude, longitude and the date. Hanoi sits at 21.0°N, 105.8°E in the Asia/Ho_Chi_Minh time zone, near the Tropic of Cancer, so its day length swings more noticeably than equatorial cities to the south but less than mid-latitude capitals to the north. Two cities at very different latitudes — say London at 51°N and Riyadh at 24°N — experience twilight over very different durations, so Fajr, Maghrib and Isha can sit hours apart even on the same calendar date. Even cities at similar latitudes drift if they sit in different time zones or follow different calculation conventions for the Fajr and Isha twilight depression angles. Hanoi and Bangkok both lie between 13°N and 21°N but their daily timetables differ by minutes because of longitude offset and method choices.