The Danish central bank leading, rather than following the ECB for a change. The DKR has been a safe-haven from European turmoil and this is likely a reaction to currency strength, first and foremost.
UPDATE: Danish central bank says they cut rates after intervening to sell DKR. I t also says it has tools to handle negative interest rates.
Like German short rates, Danish rates went negative yesterday and are sharply negative today. 2-year paper yields -0.075% today. So you are paying the Danish government to hold your money…