The time of day recorded in a transaction. The current time is maintained by the computer in minute fractions of a second and is used for a variety of synchronization purposes including determining transaction order in the event of a system failure.

Keeping Voice Over IP Synchronized
Instead of the time of day, a timestamp may be a time relative to a starting point. For example, voice packets in IP telephony (VoIP) are given a sequential timestamp by the RTP protocol so that they can be buffered at the receiving end and delivered uniformly to the listener. See NTP.