Free Astrological Forecast from Stardust Slips - expiration date?

I recently bought a group of unworn vintage slips, still with hang tags, from the late 1940s to early 1950s.
I love finding vintage clothing with their old hang tags. The tags usually give you some info about the fabric that you wouldn't have know otherwise and sometimes washing instructions.

This is a great hang tag for 'Stardust Fashion Girl Slips' introducing their new 'Miracle Fabric' which is a secret blend of nylon and rayon crepe which promises greater strength, softness and draping with minimal wrinkling.
It also includes washing instructions and recommends Lux detergent, like so many labels/tags did back then.

I love the stitching details  on the neckline of the slip.

The back of the folded hang tag has a very interesting offer, which ties in with their 'Stardust' brand. If you send in the hang tag with your name, address, birth date and a SASE, you will receive a free Astrological Forecast prepared by a world famous astrologer. Cool.