Delayed self-encrypting messages

I have a need to distribute some information fairly widely, but it's critical that it not be openly revealed before a certain date. Consider the model of an embargoed press release. Can I do this with crypto technology? Can I send someone a message, and possible a program, such that the message can only be decrypted after a predetermined date? ++PLS ----- End Included Message ----- You could do the simple way, distribute the message, then a key at the later date. To make sure the encrypted message is genuine, sign the message encrypt it, then sign it again, to ensure that people know that the encrypted text is okay.