Der Boeoegg explodiert anlaesslich des traditionellen Sechselaeutens am Montag, 13. April 2015, in Zuerich. (KEYSTONE/Ennio Leanza)..The “Boeoegg” explodes on the Sechselaeuten place in Zurich, Switzerland, April 13, 2015. The Sechselaeuten (ringing of the six o’clock bells) is a traditional end of winter festival with a parade of guilds in historical uniforms on horseback and the burning of the Boeoegg, a symbolic snowman, at 6 pm. The faster the Boeoegg explodes, the hotter the summer will be according to traditional weather rules. (KEYSTONE/Ennio Leanza)