A cherimoya is ready to eat and enjoy within 1-2 days of receiving them, as they ripen quickly (think of how fast avocados and bananas ripen on the counter). A cherimoya is ripe when it is browning on the outside and is soft to the touch. Browning will happen naturally as the fruit ripens. Please note that browning of the fruit is not indicative of a bad fruit. It means the fruit is ripe and ready for you to enjoy! Think of an avocado - they get soft very quickly, especially when you leave them out on the counter. If the cherimoya feels soft, this is the best indicator that you should eat it.
To learn more about your cherimoya, click here.