I don't have my book on Winchester ammo boxes handy but if my memory is right the numbers on the labels indicate when that label was approved for use. Winchester experimented with different codes for dating the ammo itself, for a while they used a punch code system (tiny holes in patterns stamped into the label) and, more common, various number and letter combos rubber stamped onto the box.

Ammo makers seem to avoid, as a rule, putting any clear dates of production on their ammo preferring to use codes that require you to know the system to read. They seem to have a fear (legitimate in my opinion) that the general public thinks ammo goes bad just like milk and will pass up their ammo for something with a newer date.

As to the 0P's box that general style was used from @ the 1890's to the late 1920's though there were a number of changes (some small) in the style and printing of the labels over that time period.

Edit to add; went and dug the book out... the number on the lower left of the label is the file code number, the right is the label date code (month-year) and you can safely figure your ammo was loaded after that label came into use. There should also be file and date codes on the wrap around label as well though these are sometimes lost if the label rips when the box is opened. Actual production date would have most likely been dot coded somewhere on the box labels.