In Germany, June 27 is Siebenschläfertag (Seven Sleepers Day). The weather on that day is supposed to determine the average weather of the next seven weeks. This is one of the most well-known bits of traditional farmers' weather lore remaining in today's Germany, but quite inaccurate in practice.
While it might seem that the name of the day refers to the Edible Dormouse (Glis glis), a rodent known as Siebenschläfer in German, it actually commemorates the Seven Sleepers legend. Objections have been raised that the weather lore associated with the day might have arisen before the Gregorian reform, and as at this time the difference to the Julian calendar amounted to ten days, July 7 would be the actual Seven Sleepers Day. Based on this date the prediction has a slightly increased probability, if confined to the southern parts of Germany not affected by the jet stream, where the rule seems to have originated.[1][2][3]