clockadd — adjust the local UNIX clock, once
clockadd
clockadd reads a TAI64NA time adjustment from standard input, as generated by a program such as taiclock(1) or sntpclock(1). It then adds that adjustment to the local UNIX clock.
The adjustment must be a single 16-byte packet, readable in a single call to read(2). clockadd does not require that its standard input be a stream in blocking I/O mode.
The time is always "stepped" by calling settimeofday(2). clockadd does not call adjtime(2).