Hello Danny,
Companies like Aldi & Lidl usually have a weekly changeover of 'specials', however they occasionally leave some stock a little longer.
It is difficult to say how long some of these items last, only yesterday we visited Lidl at 1pm, on the first day of the new stock, with the intention of purchasing a Slide & Negative Scanner. Unfortunately we were told they had been all sold by 10am, as it turned out the shop had only received 6. So it is advisable to visit early, if they have something you are interested in.
Best regards,
George