\ chronograph.fs
\ Date and time conversion and arithmetic

What I want:

Enter: s" 2005-09-16 18:30:55" jst
Returns: corresponding Unix time (s?, ms?, double?, float?)

Enter: -> mdt
Displays: ISO time string corr. to TOS Unix time in given zone

Enter: s" 06:40:00" today
Returns: Unix time for given time on current date local zone

Enter: now
Returns: current Unix time
(if time kept in ms, use utime instead)


Leap year (Gregorian calendar): years divisible by 4 but not by 100 plus years divisible by 400
: leapyear?  ( u -- f )
   dup  4 mod 
      if drop false 
      else dup  100 mod 
         if drop true 
         else 400 mod 
            if false 
            else true 
            then 
         then 
      then ;