A "holding period" is the period of time an asset, such as an investment, is held by an owner before he or she sells it. For example, if you purchase shares of a stock on one day and then sell them 3 months later, the holding period is 3 months. For capital gains tax reporting purposes, a long-term gain is defined by a holding period of one year and one day, while a short-term gain occurs if the holding period is one year or less.