I used to cut roses. The g’house I worked for phased out the cut roses because roses from South America could be bought cheaper, as they don’t have to spend as much for lighting/heat for V-D roses. But roses fron South America have to travel farther, and may not be as fresh as ones grown closer to home.
We would cut twice a day, once in the morning, and once in the afternoon. The roses went immediately from cut, to water (water containing citruc acid for preservation, and bleach for disinfection), to the cooler. Inside the cooler, if they were cut right (not too open, not to tight so they never open) they would last 4-5 days. Cooling would prevent them from opening too fast once cut.
If you want your roses at home to last, keep them in a cool place, and in the refrigerator at night, but at best you are probably only going to get an extra day or two out of them. If they are from South America, they might be at the end of their lifespan anyways.
When buying roses, the ones that are slightly open are prettier, but they are nearing the end of their lifespan. If they are too tighly closed, they won’t ever open, and the bud will droop on the stem after a few days.
Just for comparison, we would sometimes drop cut roses in the rows accidentally, if we came upon one that had been cut in the morning during the afternoon cut, it would be fully blown open in a few short hours.