Denmark, like Switzerland, offers negative interest rates. This is not just bills either, but in Denmark's case, rates are negative through the 2-year tenor. Swiss rates are negative through the 4-5 year sector. The Danish situation is similar to Switzerland's.
As money seeks refuge from the uncertainty in the euro zone, especially with the newly discovered redenomination risk, Denmark has experienced a surge of capital inflows. The central bank says offshore holdings of Danish bonds has risen 2.6% in the past month to DKK242 bln (~$41 bln), which is about a third of Denmark's debt.