# $EPIC: tdiff,v 1.9 2001/12/02 13:35:20 jnelson Exp $
Synopsis:
   $tdiff(<seconds>)
   $tdiff2(<seconds>)

Technical:
   * If the <seconds> argument is omitted, the empty string is returned
   * The argument is taken to be the number of seconds (floating point
     is permitted) between two timed events.  The integer part of the 
     number must be within the range 2147483647 to -2147483648.
   * $tdiff() returns the number of elapsed seconds in the following
     format:
		<integer> is taken as everything before a '.' in <seconds>.
		<after> is taken as everything after a '.' in <seconds>.
		<tsec> is <integer> % 60;
		<tmin> is (<integer> / 60) % 60;
		<thour> is (<integer> / 3600) % 24;
		<tday> is (<integer> / 86400);

	If <tday> is 0, then nothing
	If <tday> is 1, then "1 day "
	Otherwise, then "<tday> days "
    plus
	If <thour> is 0, then nothing
	If <thour> is 1, then "1 hour "
	Otherwise, then "<thour> hours "
    plus
	If <tmin> is 0, then nothing
	If <tmin> is 1, then "1 minute "
	Otherwise, then "<tmin> minutes "
    plus
	If <tsec> is not zero or all of <tday>, <thour>, <tmin> are zero,
	    or <after> exists, then 
		If <after> exists, <sec> is "<tsec>.<after>"
			then "<sec> seconds"
		If <tsec> is 1, then "<sec> second"
		Otherwise, then "<sec> seconds"

   * $tdiff2() returns the same thing that $tdiff() does, modulo:
      * "s", "m", "h" and "d" are returned instead of "seconds",
        "minutes", "hours" and "days", respectively.
      * The units indicator immediately follows the number.
      * Plurals are not indicated.
   * If a trailing space exists at the end of the string, it is removed.
   * Negative numbers are acceptable and will yield negative results.

Practical:
   These functions are useful for showing how much time has elapsed
   since a particular event. For instance, they can convert your idle
   time from the number of seconds to a more readable form.

Returns:
   A human readable string representing some elapsed time.

History:
   This function first appeared in ircII-2.2pre5

Examples:
   $tdiff(248576)      returns "2 days 21 hours 2 minutes 56 seconds"
   $tdiff(-248576)     returns "-2 days -21 hours -2 minutes -56 seconds"
   $tdiff2(248576)     returns "2d 21h 2m 56s"
   $tdiff2(-248576)    returns "-2d -21h -2m -56s"
   $tdiff2(3602)       returns "1h 2s"  Notice the absence of minutes.

