Many donors consider the time horizon of their philanthropy only after they have been giving for some years. Perhaps they created a private foundation thinking that endowing in perpetuity was not only the norm, but the only way to set things up. Perhaps their lawyer prepared the papers and they signed them without even being aware they had a choice. Perhaps they are reconsidering their positions after learning about respected philanthropists, like Bill and Melinda Gates, who plan to spend all their resources within a limited time. Perhaps they are simply undecided. In any case, both new and experienced donors have become far more thoughtful about the time frame of their giving. And setting a use-by date for philanthropy has become a common consideration. Conscious philanthropy often pays dividends for donors. And effective giving usually relies not just on how we decide to give, but for how long. All of which begs another question: Where's the time horizon for your philanthropy?