Hi everyone, I just joined today after finding this thread via an online search for info on vintage Levi's shirts. I happen to love these shirts, and have collected quite a few of them in a surprisingly large variety of colors. I've collected them in two styles: the type with metal/rivet buttons, and double chest pockets without flaps (manufactured in many different countries); as well as the "Barstow" style with western chest and pocket patterning, black/white marbled snap buttons and double chest pockets with flaps. These shirts with marbled snaps were also manufactured all over the world, but today tend to be found most often in Europe, were they were apparently marketed most heavily. I owned a couple of the metal buttoned variety back in the 90's, but it was only a few years ago (during the pandemic) that I began to "collect" them and really appreciate them for their comfort and style and great utility. I have also collected a couple of examples with Levi's advertising embroidered on the back of the shirt (as in my avatar).
What many people don't seem to realize is that the large majority of these shirts had manufacturing dates (month and year; or "quarter" and year) printed on a white tag that was located toward the bottom of the inner side stitch on the left side of the shirt. In addition to product code numbers printed in black ink on these white tags, there would almost always be a date included, such as "1Q 93", or "3QTR 94" or "11 / 95". In some cases, I've found the ink on these inner tags to be washed away completely or very faint due to that particular shirt having been washed many times, but generally these tags are still readable.
I've seen photos of tags dating from the late 1980's, but one has to consider that there were different shirt designs and different labels used over time. The earliest date in my collection (with the green-bordered Levi's label like the one in the opening post above) is from 1992. I have also seen youth shirts with the same label, but the borders are reddish rather than green. This green-bordered label was in use up to 1994. In 1995, Levi's changed the label design (the top and bottom green borders were removed), and this borderless label was also used in 1996. In 1997, the label design changed again to the "Red Tab Jeanswear" label. Somewhere between 1998 and the early 2000's, the labels were further simplified, and date tags were no longer included in the shirts.