Here's a simple alias that will return the time between when it's called and the date given:
Code:
time_until {
  ; Usage: $time_until([color:green]date[/color],[color:green] negative_time[/color])
  ; Where [color:green]date[/color] can be in any of the following formats:
  ;     January 1 1970 00:00:00
  ;     3rd August 1987 3:46pm
  ;     21/4/72 1:30:37
  ;     Wed 1998-3-27 21:16
  ; If [color:green]negative_time[/color] is a true value (not 0, $false, or $null) then negative dates will return negative values,
  ; otherwise they return 0
  var %time = $calc($ctime($$1) - $ctime)
  if ($2) return $+($iif(%time < 0,-),$duration($abs(%time)))
  return 0
}


Of course you can delete the comments when you use the code if you like (lines starting with ; ). If you don't understand any part of that I can explain it better.

Spelling mistakes, grammatical errors, and stupid comments are intentional.