It all depends on how dates are used in your PC or workstation databases and spreadsheets. There are two issues in discussing long date formats. The first is a user-input issue. Users should be encouraged to always enter dates in the long format, that is, expressing the year with four digits rather than two. The second is the display and reporting format, and this is controlled by user specified regional settings within Windows.
Computer users have their own way of making things work.
Lumberyards are really not all that different from other businesses. You have back office functions, front desk, warehousing, transportation, and security concerns. This article outlines a course of action that is applicable not only for lumberyards but for most small and medium sized businesses as well. They think the problem is centered around PCs. This after a survey of nearly five million small enterprises.