Stand‑alone layouts, such as 8.5‑inch by 11‑inch sheets and larger, should include
date information as a form of embedded version control (e.g., “Oh, I see now, that
was the old map I printed out last week. Here’s the one from this week.”). The date
also gives the audience an idea of the map’s vintage for maps that endure. Whether
the layout designer considers the map an enduring one is usually inconsequential.
Maps often contain items of value that are referred to long after the mapmaker originally thought possible. For example, the map you created only for this week’s board
meeting might take on a life of its own by getting passed around (digitally or on
paper) after the meeting, and before you know it you have created a lasting legacy
map that people have photocopied and put in their files. Let’s hope you thought to
put a date on it so that those who will pull it out of their files and “dust” it off will
instantly understand whether it is of a useful vintage or not. In summary, inclusion
of the date on a map or layout is often a preemptory practice used to mitigate unforeseen events.