Referencing Time in Excel

[jjhmbh]

We have discovered a problem in referencing time using the LOOKU
function and I haven't been able to resolve it using VLOOKUP or th
INDEX and MATCH combination

The easiest way to demonstrate the problem is to creat a list of time
from 10:00 am to 12:00 pm in 15 minute increments, then copy the lis
into the adjacent column and convert that list into the decima
equivalent. See below for what the list should look like. I expande
the decimals to the maximum number of decimals.

10:00 0.416666666666667
10:15 0.427083333333333
10:30 0.437500000000000
10:45 0.447916666666667
11:00 0.458333333333333
11:15 0.468750000000000
11:30 0.479166666666667
11:45 0.489583333333333
12:00 0.500000000000000

Now if you write a formula using LOOKUP or VLOOKUP to try to return th
decimal equivalent of a time in the left column. It works fine excep
at a few times like 10:45 and 11:30 when it returns the values fo
10:30 and 11:15 respectively.

Any help would be appreciated.

Jef

 

[Bob Phillips]

Both LOOKUP and VLOOKUP work okay for me in my (maybe limited) tests.

What data are you comparing, a time string or time value, and what formula
are you using.

--
HTH

Bob Phillips

(remove nothere from email address if mailing direct)

 

[jjhmbh]

I am using LOOKUP and use the time value.

Also I am referencing the time outside of the array. If I reference
the time in the array, it returns the correct value. For instance, if
you use the array below

<A> <B> <C>
11:00 1 11:30
11:15 2
11:30 3
11:45 4
12:00 5

The formula LOOKUP(A3, A1:B5) returns 3
But if you reference the value outside of the table, say in cell C1,
the formula returns 2.

 

[Nick Hodge]

It's the rounding at all those decimal places that is causing the
issue...try using the ROUND function on you lookup times, say to 6 decimals
and then wrap the looked up value in a ROUND function too using the same
decimals,like

=VLOOKUP(ROUND(A1,6),Sheet1!$A$1:$B$24,2,FALSE)

Using a little trial and error you will only be losing precision in seconds
or probably milliseconds.

One way at least if that precision is not necessary

--
HTH
Nick Hodge
Microsoft MVP - Excel
Southampton, England
www.nickhodge.co.uk
(e-mail address removed)

 

[Bob Phillips]

I think you are entering something incorrectly, as it returns 3 for me.

Is A1:A5 typed in, or a formula result? I can't get 2 no matter what I have
tried.

--
HTH

Bob Phillips

(remove nothere from email address if mailing direct)