now(@optional milliseconds)
Return an association list with the various components of time.
If milliseconds is not provided, the current system time is returned.
Otherwise, milliseconds is parsed to time components and returned.
now()
// [seconds:38, minute:29, hour:21, month_day:18, month:5, year:2016,
week_day:6, year_day:169, is_utc: false, is_dst:false]
now(now_seconds())
// [seconds:0, minute:2, hour:22, month_day:18, month:5, year:2016,
week_day:6, year_day:169, is_utc: false, is_dst:false]