Calculating Market Days (excluding weekends, holidays) & short days between two dates/time

Hello everyone,

I am working in excel 2000 on a worksheet to track market activity on business days (M-F only) 9.0 hrs/day (8:00am - 5:00pm only).

Scenario 1:

Column A: contains start date and time (cell is formatted: mm-dd hh:mm:ss) looks like this: 02-04 08:00:00 02-04 = 09hrs (or 1d)
Column B: contains end date and time (cell is formatted: mm-dd hh:mm:ss) looks like this: 02-06 13:30:50 02-05 = 09hrs (or 1d)
Column C: should contain the results (cell is formatted: dd hh:mm:ss) looks like this: 02 05:30:50 02-06 = 05:30:50

Scenario 2: (This is the scenario I prefer)

Column A: start date (formatted: mm-dd) looks: 02-04
Column B: start time (formatted: hh:mm:ss) looks: 08:00:00
Column C: end date (formatted: mm-dd) looks: 02-06
Column D: end time (formatted: hh:mm:ss) looks: 13:30:50
Column E: results (formatted: dd hh:mm:ss) looks: 02 05:30:50

Column G: (13:24) contains the list of holidays(9) and early(3) closings(1:00pm) that apply to market schedule with dates formatted mm-dd.
Column H: (13:24) contains a description of which days are "closed" and which days are early closings listed as "1:00 p.m".
A calendar of sorts. The early(3) days will conduct business as usual from 08:00:00 to 13:00:00.

I am currently counting the early(3) closings as "closed" instead of "1:00 p.m" because "networkdays" or "workdays" can't distinguish between them.

Also, I would like to count each 9-hour business day as 1 day. As in the above example, that time frame would equal: 02 05:30:50 (02days, 05hrs, 30min, 50sec)
Single days under 9 hrs then should be recognized in hrs only.

Many Thanks, Tom.