Stock that arrives when demand is rising makes money. Stock that arrives after demand has peaked becomes inventory you have to clear. The gap between those two outcomes usually has nothing to do with picking the wrong product. It comes down to ordering too late because nobody mapped the seasonal calendar against real lead time.
Why gut-feel season planning runs late
Most sellers start thinking about seasonal goods once they can already see demand building. Customers ask about holiday items, the topic starts trending on TikTok, competitors launch campaigns. That is when they go to 1688, search for the product, request samples, vet a supplier, then place the order.
The problem is the clock. From the moment you confirm an order to the moment goods are ready to sell in your warehouse in Vietnam, the real elapsed time is roughly 28 to 40 days under normal conditions: factory processing, domestic China delivery to a consolidation warehouse, sea freight to Vietnam (around 18 to 30 days depending on the route and carrier), customs clearance, and your own receiving and prep work. If anything along that chain stalls, add more days.
Start ordering when demand is already obviously rising, and your stock lands when demand is flattening or starting to fall. Margin thins, leftover inventory piles up, and the pressure to discount after the season hurts your next cash cycle.
Building a seasonality calendar for your category
There is no universal calendar. A shop selling home decor runs on a completely different seasonal rhythm than one selling sports gear or kids toys. You need to build yours from real signals in your category, not from a generic retail calendar.
Start with a full 12-month view and mark the anchors that apply to you.
Market-wide peaks: Lunar New Year (Tet), International Womens Day (March 8), the April 30 holiday, June 1 (Childrens Day), Mid-Autumn Festival, October 20, and then the year-end cluster of 11/11, Black Friday, Christmas, and 12/12. Most of these lift demand across many categories. For each one, you need stock ready to sell at least two weeks before the peak because buyers start purchasing early, and many categories need a full month of runway.
Category-specific peaks: Back-to-school goods spike in August and September. Outdoor and sports gear follow the dry season, roughly December through April depending on region. Household goods surge in the weeks before Tet as families clean and redecorate. Skincare and cold-weather items have a clear winter uptick. Sun protection, fans, and cooling gear follow the summer months. If you have sold through at least one year, your own sales history is the most accurate source, better than any external calendar.
Work backward from the sell date: Once you know when you need stock ready, subtract your real lead time. If you need goods on the shelf by December 20 for the Christmas window and your lead time is 30 days, the order date is around November 20. Add a buffer of at least a week for the unexpected. Write the order date into your calendar with a reminder one week before it.
Actual lead time is not the number on the 1688 listing
Suppliers post "3 to 5 day processing" and "15 to 20 day shipping" as best-case figures. The real number is every leg added together.
Add them up:
- Factory processing and packing: listed as 3 to 7 days, but during Chinese peak periods (before Chinese New Year, around China's 11/11 shopping festival) this can double because factories are running heavy order volumes.
- Domestic China delivery to the consolidation warehouse: typically 1 to 3 days.
- Consolidation: if you are ordering from multiple suppliers, the warehouse has to wait for all parcels to arrive before combining and shipping. Add 2 to 5 days depending on how many sources you are pulling from.
- Sea freight to Vietnam: roughly 18 to 30 days. Less-than-container loads (LCL) tend to run slower than full containers.
- Customs clearance and last-mile delivery: 2 to 5 days under normal conditions, longer during Vietnamese holidays when customs offices are also running at reduced capacity.
- Your receiving, QC, labeling, and prep: 1 to 3 days.
Total: 28 to 40 days in normal conditions. If you are ordering around Chinese New Year (typically late January through mid-February), add another one to two weeks because factories close and workers return slowly.
Working rule: Take the longest lead time you have actually experienced, not the shortest, and add 7 days as a buffer. Never plan an entire seasonal order around your best-case experience.
Chinese peak seasons are your risk too
Vietnamese sellers often forget that their lead time has a dependency on the Chinese calendar. Two Chinese peak periods create the biggest disruptions.
Chinese New Year (Spring Festival): Factories typically shut down from around late January to early to mid-February, with the exact dates shifting by year. In the weeks before the holiday, factories rush to clear order backlogs, and quality control can get looser than usual. In the two weeks after the holiday, many workers have not yet returned, so production runs slow. If you need stock for the late April or early summer window in Vietnam, ordering before Chinese New Year is the safe path. Ordering right after it often means delays.
China's 6/18 and 11/11 shopping festivals: Both are peak volumes for Chinese domestic e-commerce, which means factories, consolidation warehouses, and freight capacity are all stressed. Lead times in these windows can run one to two weeks longer than normal. If you need stock for Vietnam's own 11/11 in November, do not wait until October to order, because you will be competing for factory and freight capacity with China's own 11/11 wave.
How much to order, and when
There is no single formula, but a practical approach works across most categories.
Step 1: Estimate your daily sell rate during the peak window. If you sold through the same season before, use that as your baseline and adjust upward based on how your business has grown. If this is your first time in the category, look at the units sold by top shops in your niche on the platforms you sell on.
Step 2: Decide how many days of peak demand you need to cover. A Tet sales window typically runs about 3 to 4 weeks before the holiday. The 11/11 real burst is usually about 2 weeks of concentrated demand.
Step 3: Multiply daily rate by days covered, then add 15 to 20 percent as a buffer for supplier delays, unexpected demand spikes, or defective units at receiving. This is the quantity you need in your warehouse before you open the campaign.
Step 4: Subtract your lead time from the date you need stock ready. That is your order date. Set a calendar reminder one week before it.
One point that often gets overlooked: seasonal order quantities are frequently much larger than your original test batch. If your test was 100 units, a seasonal order might be 500 to 1,000. Many suppliers have tiered pricing and only hit a better unit price above a certain quantity. Confirm the price at your actual intended quantity before you finalize the landed-cost calculation.
When the seasonality calendar conflicts with cash flow
Ordering early is correct from a logistics standpoint, but it can collide with the reality of your cash position. Capital is tied up in the previous batch, or you do not have enough liquidity to commit a large order all at once.
A practical way to handle this is to split the order into two placements:
- First placement: a base quantity sufficient to cover minimum expected sales during the peak, ordered early on schedule.
- Second placement: a top-up once demand starts visibly building, but timed so the goods still arrive while the peak is ongoing.
The second placement has to be locked no later than four to five weeks before you need the stock, not when you are already running low. Running out during a campaign and waiting for a reorder to arrive is worse than being slightly conservative on the first batch.
A seasonality calendar compounds over time
In your first year selling a category, you will probably be late at least once. That is expected. The important thing is to record what happened: which windows sold strongly, when they started and ended, and what quantities you needed. By the second year your calendar will be more accurate, and by the third it will be a real operational asset.
Write down the actual lead times you experienced for each order: which batches arrived on schedule, which ran late and by how many days, and why. This data does not exist in any guide. It only lives in your own order history.
Bottom line
Seasonality is predictable. The real discipline is ordering on the logistics calendar, not on the market-feel calendar. Build your category's seasonality map, stack every leg of the real lead time, and place the order before the market starts heating up. Stock that arrives at the right moment is a competitive edge. Stock that arrives two weeks late is a clearance problem.