Sunrise Cavalier (DBL) from Innistrad: Double Feature, available at 401 Games Canada.

• Rarity: Uncommon
• Finish: Normal
• Artist: John Di Giovanni
• Card Text:
  Trample, haste
  If it's neither day nor night, it becomes day as Sunrise Cavalier enters the battlefield.
  Whenever day becomes night or night becomes day, put a +1/+1 counter on target creature you control.