One way to do it would be to pass it in as an argument or other when you run ChucK. This example uses stdin to read the output of a <date> command in the shell: // TestDate.ck Perry R. Cook, Dec. 2014 ConsoleInput stdin; // gonna read from here stdin.prompt("") => now; // wait until something comes in string datetime; // date and time string datetimenow; // plus time since chuck invoked tacked on while (stdin.more()) { stdin.getLine() => datetime; } // read input datetime.setCharAt(9,'-'); // replace time string colons datetime.setCharAt(12,'-'); // with dashes instead datetime+"-"+Std.ftoa(now/second,4) => datetimenow; // tack on time since chuck invoked <<< datetimenow >>>; // If you want to continue making updated unique // strings, just keep redoing the datetimenow line 1.5*second => now; datetime+"-"+Std.ftoa(now/second,4) => datetimenow; // tack on time since chuck invoked <<< datetimenow >>>; To use this: date +"%m%d%y-%T" | chuck TestDate.ck Outputs (date-H-M-S-now): "120614-15-00-09-0.0000" : (string) "120614-15-00-09-1.5000" : (string)