Tap up to two target creatures. Those creatures don't untap during their controller's next untap step.
Draw two cards, then discard a card.
If you chose targets for Snow Day as you cast it, and none of those targets are legal as it tries to resolve, it will be removed from the stack and do nothing. You will not draw or discard.
You may choose tapped creatures as targets. Those creatures won’t untap during their controller’s next untap step.