The Palmtop Appointment Book is a very good application, but sometimes there is a need for more flexibility. For example, you may have an event or series of events that are dependent upon another event that may not have a set date, like a rocket launch date. In the scheduling of rocket launches, all events are written in terms of launch date. It may be that a given analysis is due 30 days before the Launch Date, but the Launch Date may change at any time. This can make it a real nightmare to try do any planning/scheduling in either the Appointment Book or on a paper calendar.
The solution to the problem is to create a schedule in Lotus 1-2-3, using the built-in date arithmetic feature. Then, when you change the Launch Date, all other dates dependent on it will automatically recalculate. The concept will become clearer using the Launch Date example.
Suppose we are going to launch the U.S. Space Shuttle and have selected the Launch Date. There are three other events that depend upon this date: Assemble the vehicle (Assmb), Move the vehicle to the launch pad (Move); and Fuel the vehicle (Fuel).
Enter TASK in cell A1 and DATE in cell B1 as headers. Enter all of the event titles in column A, as shown in the screen below.
Setting up a Appointment Book rocket launch schedule in Lotus 1-2-3. Formulas in cells B3-B7 adjust date as Launch date changes.
Now move the cursor to cell B2 and format this column for dates. Since I prefer the long international date format of MM/DD/YY we will use this format in this example. You can use any date format supported by 1-2-3.
Press (MENU) Range Format Date 4(Long Intl) and using the DownArrow, highlight the area to be formatted, in this case B1 through B7, and press (ENTER). Now we can enter the projected date for the launch of June 30, 1996 in B7 by typing @date(96,6,30) and press (ENTER) (the date format is always entered as @date (year,month,day)).
Next, assign a formula to our tasks that will assign them dates based upon the Launch date. Let's suppose that Assmb needs to be completed 45 days before launch date, Move 30 days before launch and Fuel 2 days before launch. Go to cell B3 and press +B7-45 and press (ENTER), the date 05/16/96 shows up next to Assmb as our completion date. Go to cell B4 and enter +B7-30 and press (ENTER). Finally go to cell B5 and enter +B7-2 and press (ENTER). Now we have all of our tasks with their completion dates dependent upon the launch date. Now save the file by pressing (MENU) File Save and name it Launch and press (ENTER).
When the launch date changes, all you have to do is open the spreadsheet and edit the launch date, and all of the other dates will change in accordance.
Bruce Martin
Internet Email bt511@torfree.net
CompuServe ID: [72561.3224]
Tom Gibson
Technical Editor - HP Palmtop Paper
E:-mail: tom_gibson@thaddeus.com