A timestamp is the current time of an event that is recorded by a computer. Through mechanisms such as the Network Time Protocol ( NTP ), a computer maintains accurate current time, calibrated to minute fractions of a second. Such precision makes it possible for networked computers and applications to communicate effectively. The timestamp mechanism is used for a wide variety of synchronization purposes, such as assigning a sequence order for a multi-event transaction so that if a failure occurs the transaction can be voided. Another way that a timestamp is used is to record time in relation to a particular starting point. In IP telephony , for example, the Real-time Transport Protocol ( RTP ) assigns sequential timestamps to voice packet s so that they can be buffer ed by the receiver, reassembled, and delivered without error. When writing a program, the programmer is usually provided an application program interface for a timestamp that the operating system can provide during program execution.