We have recorded 138 changes to a release date since we started tracking them. Every one of them moved the date later. Not a single release in our records has ever been brought forward.
How far do dates move?
The median change is 3 days. The largest is 253 days, which is most of a year. A date that moves tends to move by a few days, and a small number move by months.
That asymmetry is worth holding on to when you read a release calendar. A date on an announcement is the earliest the product is expected, and the distribution of what happens next has one tail.
Why do dates only slip?
We can only report what the record shows, not the reason inside a manufacturer. What the pattern is consistent with is a date set early, announced for planning, and adjusted when printing, licensing or distribution takes longer than planned. There is no mechanism that makes a product arrive before it was made.
What should a collector do with a release date?
Treat an announced date as a floor rather than a plan. If something depends on the product arriving by a particular day, the announced date is not the right date to depend on. Our release calendar records the date a manufacturer stated and the date it last changed, so you can see which have moved and which have not.
How we count a date change
A change is recorded when a date we had already published is replaced by a different one from the manufacturer. Dates added for the first time are not changes, and a release whose date has never been stated is not counted at all. The figures above cover the 138 changes where we hold both the old date and the new one.
