Balduvian Conjurer

• WWizards of the Coast2008-08-01
  Official Ruling
  A noncreature permanent that turns into a creature can attack, and its abilities can be activated, only if its controller has continuously controlled that permanent since the beginning of their most recent turn. It doesn’t matter how long the permanent has been a creature.
• WWizards of the Coast2008-10-01
  Official Ruling
  If an affected land later loses the supertype snow, Balduvian Conjurer’s effect doesn’t end. The land will remain a creature until end of turn.

Rulings via Scryfall