Dates are normally classified as soft, semi-dry or dry. There are many varieties of dates but they all go through four stages of development. Chimri is the first stage and lasts for a period of 17 weeks, followed by a six-week period called the Khalal stage. These are the stages of growing from pollination to full size. The last two stages are Rutab, a four-week stage of ripening, and the Tamar, stage when they are fully ripe. Dates are harvested during one of the last two stages, depending on the variety, and preserved by cold storage.
Clean dates by placing them on a screen tray or in smaller quantities, in a colander and rinsing them with a light spray of water. Then place them in an area where the temperature is approximately 90 degrees F, and allow them to air dry.
Place dry dates in the refrigerator to keep them for eating or using in recipes within the next few months. Dry dates will keep for two or three months with no refrigeration, but will last up to eight months in the refrigerator. Soft dates will not last quite as long.
Freeze dates to preserve for later use. Slightly unripe dates will last a few months longer than fully ripe dates, but they will both last for over a year.
Cut date pieces to a desired shape or size and place in a fruit dehydrator. Once dehydrated, place the dates in a storage container. They do not need to be refrigerated and will last up to a month or two. If you choose to put them in the refrigerator, seal tightly to prevent rehydration and spoiling from gases given off from other fruit.