Seasonality in e-commerce: sales calendar, stock and ad budget planning for the year ahead.
Author: Borys Terlecki · marketplace sales and implementations at Commercraft · updated: September 2026
In brief
Sales peaks recur in the same weeks yearly: Black Week on 23-29 November 2026, Prime Day, Smart! Weeks and Allegro Days, so you can plan them ahead.
You prepare on four fronts at once: stock, logistics, advertising and customer service. A weak link in any one of them wastes the whole peak.
German dates and delivery expectations differ from Polish ones, so you plan the PL-DACH corridor separately.
In e-commerce the year is not flat. Some weeks multiply sales, some months go quiet. Polish online shops earn 28% of annual revenue in the fourth quarter alone.
These peaks have dates, so you can plan for them. Below is the 2026/2027 season calendar with promotion dates on Allegro, the largest marketplace in Poland, and on Amazon, when to order stock, and how the Polish and German calendars differ.
Most sales swings come back in the same weeks every year: Black Friday and the pre-Christmas period, clearance sales, the start of the school year and industry seasons. Platforms add their own events, announced well in advance.
| Event | Date | What it means for your plan |
|---|---|---|
| Valentine's Day | 14 February | A short peak in gifts, jewellery and cosmetics. Stock is ordered in December |
| Easter | 28 March 2027 | Earlier than in 2026, so garden and decoration seasons start with a different lead time |
| Muttertag (Germany, Austria) | 9 May 2027 | Second Sunday of May. If you sell in DACH, a separate date from Polish Mother's Day |
| Mother's Day (Poland) | 26 May | Fixed date, two weeks after the German one. Plan campaigns for each market separately |
| Smart! Weeks | 11-20 May 2026 | An Allegro event for members of Smart!, its paid delivery programme. The next edition usually falls in the same window, so reserve stock and ad budget for May |
| Prime Day | 23-26 June 2026 | In Poland, Germany, Austria, France, Italy, Spain and the United Kingdom. Four days, up from two |
| Allegro Days | 7-13 September 2026 | A dress rehearsal before the fourth quarter. A good test of prices and shipping capacity |
| Prime Big Deal Days | 6-7 October 2026 | Announced for the United States, unconfirmed for Europe. Check before you plan your budget |
| Singles Day | 11 November | Opens the November promotion wave, especially in electronics and on Asian platforms |
| Black Week | 23-29 November 2026 | A whole week instead of a single day. This tests warehouse and service capacity |
| Black Friday | 27 November 2026 | The peak of the peak. Prices and stock levels must be set the day before |
| Cyber Monday | 30 November 2026 | Closes Black Week, stronger in electronics and digital services |
| Fourth quarter | October-December | 28% of annual revenue for Polish online shops. Stock for it is ordered by September |
Sources: Allegro announcements on Smart! Weeks and Allegro Days 2026, Amazon announcements on Prime Day (23-26 June 2026) and Prime Big Deal Days, Shoper data from around 20,000 shops on the fourth-quarter share, 2027 holiday calendar. Checked: September 2026.
Good peak preparation covers several areas at once:
stock: inventory of your bestsellers, calculated from last year's sales curve instead of the annual average,
logistics: shipping capacity and returns handling at the peak. If your warehouse cannot cope in November, choose a 3PL provider in the summer,
advertising: budgets planned week by week ahead of the peak, with bids raised before your competitors raise theirs,
customer service: team and automations ready for many times more messages and returns.
A weak link in any of them can waste the whole peak. A sold-out bestseller or blocked shipping means lost sales that never return, because the buyer bought elsewhere. On marketplaces there is a second loss: late shipments hurt your account metrics exactly when traffic peaks.
The most common mistake is last-minute preparation. Counting back from Black Week (23-29 November in 2026), close orders with Asian suppliers in summer and domestic stock by September.
Warm up campaigns and improve product pages before traffic rises. On a marketplace, offer history counts: a product with sales and reviews before the peak enters it stronger. That is why Allegro Days in September are a good test before November.
The quiet season is for work there is no time for at the peak: cleaning up product data, testing new markets and channels, improving product pages and preparing for the next peak. January and February are also the best time to join a new platform, as registration, verification and first listings take several weeks.
A well-used off-season builds an advantage that shows in season.
German and Polish calendars differ at specific points. Muttertag falls on the second Sunday of May, 9 May in 2027, while Polish Mother's Day is always on 26 May. Easter in 2027 falls on 28 March in both markets.
Delivery expectations differ too, and at the peak they decide the basket. German shoppers are among the most demanding in Europe when it comes to speed. In Sendcloud’s European survey, 48% of shoppers had abandoned a basket because of delivery, and 76% would wait longer to avoid paying for shipping. Since March 2026 the free delivery threshold on Amazon.de without Prime has been 49 €.
Shipping and returns for this corridor are covered in our guide Cross-border logistics PL-DACH.
We build a sales calendar for your categories: a stock forecast for the peaks, an ad budget planned week by week, offers prepared ahead of platform events and a plan for the quiet months. We run accounts on Allegro and Amazon day to day, so we know when platforms announce events and how long you have to submit offers.
Tell us your categories, and we will tell you which dates in the table matter to you. Before you commit, run the numbers in our marketplace ROI calculator.
Borys Terlecki – marketplace sales and implementations at Commercraft. He previously worked on the operator side of marketplace platforms (Mirakl, Munich) and today onboards brands on marketplaces in Poland and the DACH region and runs their accounts.
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