Gang:

Here's a script that calculates the number of days between two dates. Maybe there's some snippets here that someone can use !

There must be a better ( faster ) way of doing this though ? Help me - but please don't make me look like an idiot for submitting this monster !

Plus - I think the code here has a minor ( one or two day diff) bug in it. Cudo's and admiration to anyone who can figure it out !


code:
; Calculate days between dates ...
break on

if $pipe
 redirectoutput ( $pipe )
endif

dim $julian_runsum[13]

$julian_runsum[00] = 0
$julian_runsum[01] = 31
$julian_runsum[02] = 59
$julian_runsum[03] = 90
$julian_runsum[04] = 120
$julian_runsum[05] = 151
$julian_runsum[06] = 181
$julian_runsum[07] = 212
$julian_runsum[08] = 243
$julian_runsum[09] = 273
$julian_runsum[10] = 304
$julian_runsum[11] = 334
$julian_runsum[12] = 365

?"Enter date [YYYY/MM/DD] : " gets $date1
?"Enter date [YYYY/MM/DD] : " gets $date2

$y1 = val(substr($date1,1,4))
$m1 = val(substr($date1,6,2))
$d1 = val(substr($date1,9,2))

$y2 = val(substr($date2,1,4))
$m2 = val(substr($date2,6,2))
$d2 = val(substr($date2,9,2))

gosub the_days_between

?"Days between  = $days"

exit
;----------------
:the_days_between
;----------------

$julian_y = $y1
$julian_m = $m1
$julian_d = $d1

gosub calc_julian

$t1 = $julian_date

$julian_y = $y2
$julian_m = $m2
$julian_d = $d2

gosub calc_julian

$t2 = $julian_date
if ( $y1 <> $y2 )

 if ( $y1 > $y2 )

  $max = $y1
  $min = $y2

  $julian_y = $y2
  $julian_m = 12
  $julian_d = 31

  gosub calc_julian

  $t2 = $julian_date - $t2

 else

  $max = $y2
  $min = $y1

  $julian_y = $y1
  $julian_m = 12
  $julian_d = 31

  gosub calc_julian

  $t1 = $julian_date - $t1  

 endif

 $i = $max

 while $i > ( $min + 1 )

  $leapyear_y = $i

  gosub isleapyear

  $years = $years + 365 + $leapyear

  $i = $i - 1

 loop

else

 $days = $t1 - $t2

 return

endif

$days = $t1 + $t2 + $years 

return

;-----------
:calc_julian 
;-----------

; input  : date as $julian_y $julian_m $julian_d
; output : days as $julian_date

$total = $julian_runsum [ $julian_m - 1 ] + $julian_d

if ( $julian_m > 2 )

 $leapyear_y = $julian_y

 gosub isleapyear

 $total = $total + $leapyear

endif

$julian_date = $total

return

;----------
:isleapyear
;----------

if (( $leapyear_y * 4096 / 400 ) & (4095) ) = 0

 $leapyear = 1

else

 if (( $leapyear_y * 4096 / 4 ) & (4095) ) = 0 and (( $leapyear_y * 4096 / 100 ) & (4095) ) <> 0

  $leapyear = 1

 else

  $leapyear = 0  

 endif

endif

return

Shawn.

[This message has been edited by Shawn (edited 08 June 2000).]