The expensive mistake is a single “SEA holiday calendar” in a shared drive. Singapore’s National Day parade closures, Thai Songkran, Vietnamese Tết, Balinese Nyepi and Javanese mudik, and Philippine Holy Week close different parts of a supply chain. One pauses a government counter, one pauses a factory belt, one turns the lights off on an entire island. Treat the five countries as five calendars that happen to sit in the same sales region.
Five hard windows
Singapore. A multicultural gazette: two days of Chinese New Year (17–18 February 2026), Good Friday (3 April), Vesak Day (Sunday 31 May, with Monday 1 June in lieu), Hari Raya Puasa (21 March), Hari Raya Haji (27 May), Deepavali (8 November, with 9 November in lieu), and National Day on 9 August (with 10 August as the holiday when the weekend collision applies). Parade rehearsals restrict roads. Do not assume Malay or Indian colleagues are off for Chinese New Year, or the reverse. Confirm the MOM list before you mail a customer holiday notice — Islamic dates can still move with the competent authority.
Thailand. Songkran is usually 13–15 April, sometimes extended by Cabinet bridge days. Treat mid-April as a full-week pause for offices and domestic freight and ship before 10 April. Royal commemorations close public offices; beaches stay open. Coronation Day on 4 May 2026 sits inside the wider May crush that also hits China, Japan and Vietnam. Late December is peak island pricing.
Vietnam. Statutory Tết is short; plant practice is not. Lunar New Year’s Day 2026 is 17 February, shared with China, with a different restart curve. 30 April Liberation Day plus 1 May Labour Day is a spring travel peak. Write Tết delay language into contracts and collect a written restart date from each factory in January. Hung Kings Day on 27 March is a single-day pause that still surprises buyers who only marked February.
Indonesia. Nyepi on 19 March 2026 is a near-total pause on Bali, including the airport. Java feels Eid homecoming instead. Islamic dates can move with the moon; 2026 Hari Raya Puasa aligns with Singapore on 21 March and Hari Raya Haji on 27 May. Collective leave (cuti bersama) is a separate decree and can stretch one festival into a week. Lock freight two weeks before Lebaran. Independence Day on 17 August is a midweek national day that coincides with Korea’s Liberation Day substitute — relevant if you run Surabaya and Busan in the same programme.
Philippines. Regular holidays and special non-working days pay differently. Holy Week (Maundy Thursday 2 April and Good Friday 3 April 2026) and Christmas–New Year are the long gaps. BPO sites usually roster rather than close; read the customer contract. 1–2 November (All Saints’ / All Souls’) affects family travel and support staffing. Day of Valor on 9 April sits between Holy Week and Songkran — a quiet trap for Manila–Bangkok dual coverage.
Three sentences that belong in the purchase order
- Delivery dates slide when the plant’s or port’s public holiday calendar — not the signing entity’s — makes performance impossible.
- Capacity for Tết, Songkran and Lebaran is confirmed fourteen days prior; after that the delay risk sits with the buyer.
- Faith-based dates follow the local competent authority for the year, not a frozen schedule in this annex.
Copy the tables from Singapore, Thailand, Vietnam, Indonesia and the Philippines. How those tables are built is in how we compile dates.
What a week-by-week buyer actually does
In January, write to every Vietnamese plant for a Tết restart date and put the last sailing before that date in the purchase order. In March, decide whether Nyepi will touch any Bali-origin cargo — if it will, that aircraft or boat simply does not move on 19 March 2026. In early April, treat Songkran as a Thai-week blackout and Holy Week as a Manila-week blackout; they are not interchangeable. In late April, do not schedule a joint China–Vietnam–Thailand acceptance test. In May, re-check MOM and Indonesian gazettes for Vesak and Hari Raya Haji before you mail a customer holiday notice.
Hotels and inter-island flights during Songkran and Tết price like peak Christmas in Europe. If the trip is discretionary, the week after each festival is cheaper and quieter. If the trip is a factory audit, do it in the second full week after restart, not the first: the first week is backlog, missing staff and a partly new line. A shared spreadsheet that has one colour for five countries will hide exactly those offsets. Keep five rows or do not keep the sheet.
Ports, airports and the “open city” illusion
A busy tourist beach during Songkran does not mean the Laem Chabang documentation desk is staffed. A lit-up casino strip in Macau does not mean a Zhuhai customs broker is answering. Bali’s Nyepi is the extreme case: if the airport is closed, cargo does not move because the island does not move. Elsewhere the failure mode is subtler — half a warehouse team on leave, a single licensed signatory out of town, a trucking firm that quoted “SEA working days” and meant Singapore’s gazette.
For multi-country travel planning across these markets and North Asia, use 2026 business-travel windows. For how weekend collisions and substitutes differ, see substitute holidays explained. Lunar New Year length differences with China are in Lunar New Year 2026.
Ramadan, Lebaran and the manufacturing calendar
Even when Hari Raya Puasa is a single gazetted day, the weeks around it change factory output in Muslim-majority areas of Indonesia, southern Thailand and parts of Singapore’s workforce. Night shifts shorten during Ramadan; the homecoming before Lebaran empties Java’s industrial belts; the return week is backlog. Treat the fortnight before and after the gazetted Eid date as reduced capacity, not as full production with one day missing. Lock containers and packaging materials fourteen days out, and do not invent a fixed “Lebaran always falls in April” rule — 2026’s March dates are a reminder that the moon does not respect your quarterly OKR.
Nyepi remains the special case: Bali’s pause is civic and near-total, not merely industrial. If any bill of materials, sample, or VIP guest depends on a Denpasar connection on 19 March 2026, move it. Java will not save you that day if the aircraft cannot leave Bali.
BPO, shared services and the “always on” myth
Philippine BPO sites often roster through regular holidays, but Holy Week and the Christmas–New Year corridor still thin the benches. Read the customer contract: some require continuous coverage with holiday differentials; others allow reduced severity. All Saints’ and All Souls’ on 1–2 November look minor on a gazette and major in family travel — expect longer handle times and more absences even when the site is “open.”
Singapore shared-services hubs covering the region must not copy-paste a China holiday notice to Malay or Indian customers, or a Deepavali notice to everyone. Segment the holiday mailer by customer geography and by the desk that serves them. A single “SEA closed” banner is how you lose trust with a Thai account that was open all week while Bangkok was in Songkran and your banner lied.
A buyer’s wall chart for 2026
January: collect Vietnamese restart letters. March: Nyepi 19th and Hari Raya Puasa 21st. Early April: Holy Week then Songkran — two different blackouts. Late April–early May: do not run a three-country acceptance test. End of May: Vesak and Hari Raya Haji — re-check MOM. August: Singapore National Day week and Indonesian Independence Day. November: Philippine All Saints’ week and Singapore Deepavali in lieu. Keep the chart on one page; if it needs two pages you are tracking too many colours and not enough named plants.