Provided is a method for enabling a device without a secure clock to make
a determination on the expiration of encrypted content. When the device
receives content, the device also receives the content provider's policy
on access. This information provides an ATI in UTI units which is to be
associated with the content for the purpose of managing the content's
expiration. The ATI is converted to the device's DTI units and the DTI is
then used to control the availability of the content for decryption and
use. The claimed subject matter permits the existence of tolerance,
determined by content policy, in the conversion between UTI and the DTI,
as well as in the depletion of the ATI. To move or copy content which has
an associated remaining ATI, the device converts the ATI into UTI units
and provides converted ATI to the target device in conjunction with the
associated content.