Environments with unreliable delivery may result in faltering presentation of multimedia objects, due to missing time stamp deadlines. This may be alleviated by introducing more flexible time stamping. To avoid this, additional MPEG-4 object time information is sent to the client. This requires a new dedicated descriptor, carried in the Elementary Stream Descriptor. The new more flexible timing information will have two features. First, instead of fixed start and end times, the duration of an object can be given a range. And second, the start and end times are made relative to other multimedia object start and end times. This information can then be used by the client to adapt the timing of the ongoing presentation to the environment, while having more room to stay within the presentation author's intent and expectations.