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Debra Dalgleish
 
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If you round the numbers, does it give the results you expect? For example:

=IF(AND(ROUND(D$1,10)=ROUND($B2,10),ROUND(D$1,10) <ROUND($C2,10)),
"IN","NOT IN")

Ian wrote:
Hello Debra,

Thank you. You are right.

In order to increase the flexibility of the sheet the
interval headings reference an opening time cell and an
interval cell. The first heading (D1) references the
opening time cell and the other interval headings are
constructed using the formulas (in E1) =d$1+interval
cell, (in F1) =e$1+interval cell etc. I have been
careful to format the cells with a custom format hh:mm:ss.
The interval cell for this example contains 00:15:00
formatted hh:mm:ss.

I want to be able to sample using a variety of intervals.

You've found the source of the problem - but not the
solution. How does this inaccuracy creep in? What can
be done to gaurd against? Excel not to be relied on?
What seems a very straightforward application of excel
has caused me..grief!

Thanks for your help. Ian

-----Original Message-----
How did you enter the times in row 1? If they're


formulas, they may be

slightly greater or less than the time that's being


displayed.

You could type the first two numbers, and select them
Then point to the fill handle (the small black square at


the bottom

right of the selection)
When the pointer changes to a black plus sign, drag


across, to the last

column

Ian wrote:

Hi,

I recently constructed a large spreadsheet for a
colleague which, amongst other things samples at
intervals the number of staff available (that is not


on a

break, not on leave , not sick etc.) based on a staff
roster.

For example at 10:15, 10:30, etc how many staff are
available to take calls during that interval.

A very simplified version of the problem is as follows:

Row 2
Column A = a list of names
Column B = each member of staffs shift start time i.e.
08:00
Column C = each member of staffs shift end time i.e.


16:00

Row 1, starting at Column D is filled with each


interval

i.e. 08:00, 08;15, 08:30, 08:45..up to, for example,
20:00.

The following formula is entered into each cell


starting

at row 2, column D up to the final interval, in this


case

20:00, for each name - constructing a kind of truth


table.

=IF(AND(D$1=$B2,D$1<$C2),"IN","NOT IN")

Seems straightforward enough, I hope. This works as
expected - but only up to a point! If you constuct


this

table and enter the following data you may encounter


an

unexpected problem.

For the 1st staff member Column A row 2 give a start


time

of 08:00 and an end time of 14:45. This should show
correct. The staff member is showing as "NOT IN" at


the

14:45 interval. Now increase the end time for the same
staff member by 00:15 intervals. At 15:00 the table
still reads correctly - "NOT IN" at 15;00. At 15:15
however... If you have the inclination continue this


and

each time see what the table shows.

Apologies for being so verbose.

Does anyone have an explanation? Is this a known
problem? Any solutions?

Thanks in advance. Ian



--
Debra Dalgleish
Excel FAQ, Tips & Book List
http://www.contextures.com/tiptech.html

.




--
Debra Dalgleish
Excel FAQ, Tips & Book List
http://www.contextures.com/tiptech.html