Crypto airdrops can last for a variety of different lengths of time. Some airdrops may only last for a few days, while others may last for weeks or even months. The length of time an airdrop will last typically depends on the size and scope of the airdrop. For example, a large airdrop with many participants may last longer than a smaller airdrop with only a few participants. Airdrops that are part of a larger promotion or marketing campaign may also last longer than standalone airdrops.