They will last the longest if you give them a fresh cut under water once you bring them in the house. Use a sharp knife and cut about and inch above the old cut. The stem has many little straws that try to suck up water. When you cut them outside, they suck up air and clog the phloem. Give them a new cut and they will last at least a week!
How long do fresh cut daffodils last?
about a week, some say a little less, but I've always been quite happy with how long daffodils lasted for me....espcially compared to other flowers.