That depends on how you dry them. If you have a dehydrator that reaches 160°F (70°C), it will take only one to two hours. If you dry them at a more moderate 130°F (55°C), it may take six to eight hours. If you dry them in the sun, it will take four or five days (much longer if one of those days is rainy).
Whatever method you use, you’ll know they’re done when they feel leathery and have no discernable pockets of moisture.