Answer by manatwork for How to get milliseconds since Unix epoch?

To avoid calculations to get the milliseconds, command line JavaScript interpreters may help:

bash-4.2$ node -e 'console.log(new Date().getTime())' # node.js1364391220596bash-4.2$ js60 -e 'print(new Date().getTime())'       # SpiderMonkey1364391220610bash-4.2$ jsc -e 'print(new Date().getTime())'        # WebKit 1364391220622bash-4.2$ seed -e 'new Date().getTime()'              # GNOME object bridge1364391220669

Packages containing those interpreters on Ubuntu Eoan:

• node.js: nodejs
• SpiderMonkey: libmozjs-60-dev
• WebKit: libjavascriptcoregtk-4.0-bin
• GNOME object bridge: seed-webkit2