A B C D E F G H I J K L M N    
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3 Example: Date Inclusivity
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5 n  Uses  Con, DiffD, FStep
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7 The Business Functions library has the following rule for determining lengths of time:
8 Include the Start Date but Exclude the Finish Date.
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10 Why?
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12 n  It's because a date refers to an absolute point in time, the beginning of a day, irrespective of whether that day is the Start or Finish of something.
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14 n  If a date referred to a different point in time (the start or end of a day) depending on whether it was a Start or Finish date, you (and the library)
15         would always have to remember the purpose of the date, not just the date itself.
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17 n  It's therefore fundamentally that a date is a point in time (the start of a day, 00:00 hours) and not a period of time.
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19 n  Finally, it's to be consistent with Excels Date and Financiial Functions such as YEARFRAC and  DAYS360. BF Excel
20     YEARFRAC   0.0055   0.0055  
21    30 Jan 08  1 Feb 08   DAYS360   1.0000   1.0000  
22 Consequences:        
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24 If a payment runs up to and includes the 30th June, it's finish date is the 1st July:
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26  1 Jan 03  1 Jul 03 500  
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28 n  If a series of stepped payments run up until the 30th June each year, they change on the 1st July, whether you used 'From' dates or 'To' dates
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30 From Dates Annual Rate To Dates Annual Rate
31  1 Jan 03 100  1 Jul 03 100
32  1 Jul 03 200  1 Jan 04 200
33  1 Jan 04 300  1 Jul 04 300
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35  1 Jan 03  1 Jan 04
36 FStep   150    
37 TStep   150    
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