The list changed time zone

The send hour was chosen once, in the first month, by whoever set the platform up, and it was chosen from the office clock.

Nine in the morning, local. The cutoff for next-day delivery at four in the afternoon, local. The basket reminder an hour after the basket. Set once, running ever since, and correct for about eleven months of the year.

In August the list moves and the settings do not.

A large part of a Gulf list is not in the Gulf this month. The households are in London, in Cairo, in Tbilisi, in Sarajevo, two or three hours west of where the schedule believes they are. A European list has gone as well, out to the coast and out of the commute the send time was quietly built around. So the message that lands at nine on a working morning arrives at six for one household and after eleven at night for whoever travelled the other way, and the replies come in from airports.

Nobody catches it, because the report has no column for where the customer was standing. Open rates soften. Somebody writes August in the comment box, and August is allowed to explain anything.

The useful question is not what hour to send. It is who this is for over the next four weeks, which is not the person the schedule was built for. A holiday inbox is read later, on a phone, with more time and less patience than a commute allowed. A next-day cutoff means nothing to a customer whose parcel is going to a flat nobody is in, and a delivery promise made to an empty flat is worse than no promise at all.

Four weeks is long enough to be worth the ten minutes. The correction costs nothing except somebody noticing that the customer moved and the schedule stayed.