Data-Board DATMAG "the magnetic permanent calendar"

actually i've never heard of this one before even it is obviously a german design piece and made by herlitz if i remember the herlitz h correctly...

it seems to be rare or nobody knows who manufactured it because the cartboard box is missing....? at east i haven't found any informations about this one yet...

you have to place an magnetic sticker on the metal board to complete the date... see last pic please

i thought it's pretty cool... my guess is 1970s because of it's op art neighbourhood