169dabe8_NetPDL_Expressions__NetBee___Description
[Variable] $timestamp_sec [Data type] number [Description] 
The timestamp is expressed by two different variables that look very similar to the struct timeval structure defined in BSD sockets. This variable keeps the number of seconds elapsed since midnight (00:00:00), January 1, 1970, coordinated universal time, according to the system clock of the host who captured the packet.
NetPDL Expressions [NetBee]
Description