Multi-channel
Timezone traps in marketplace order dates
Dates look like the simplest field in the order payload. They are the one that quietly corrupts reporting across every channel you sell on.
Three different dates for one order
The API gives you a timestamp, usually in UTC. The seller dashboard shows it in the marketplace is chosen timezone. You are sitting in a third one.
For an order placed mid-afternoon these all agree. For one placed near midnight they do not, and near midnight is a busy time for consumer purchases.
Where it actually hurts
- Month-end totals that do not match the platform is own report
- Orders that appear to be missing from a date-range sync
- A dispatch deadline that looks a day further away than it is
- Daily sales figures that are consistently slightly wrong in both directions
The second one is the dangerous case: an order that falls outside your date filter is not obviously absent, because nothing tells you what you did not fetch.
Store UTC, display local
The rule that solves most of this: keep the raw UTC timestamp exactly as the API gave it, and convert only when showing it to a human. Never overwrite the original with a converted value.
Once you have stored a converted date and forgotten which timezone it was converted from, the information is unrecoverable.
Daylight saving makes it worse
Offsets change twice a year, and the change dates differ by country. Code that applies a fixed offset is correct for part of the year and wrong for the rest, which is the hardest kind of bug to notice because it half works.
Use a real timezone identifier rather than a fixed offset, always.
Reconciling with the platform report
When your numbers disagree with the marketplace is, the boundary is the first thing to check. Pull the same range from both, sort by timestamp, and look at the first and last few rows - the discrepancy is almost always at the edges.
If the middle matches and the edges do not, it is a timezone question, not a data-loss question. That one check saves a lot of unnecessary panic.
Pick one reporting timezone
For multi-channel sellers, choose a single timezone for all your own reporting and convert everything into it. It will not match any individual platform is view perfectly, and that is fine as long as you know which one you chose.
Consistency matters more than matching any particular platform, because the comparison you care about most is between your own months.