=SUMPRODUCT(--(A2:A20=--"2005-09-16 08:15"),B2:B20)

--
HTH

Bob Phillips

"Zakynthos" <Zakynthos@discussions.microsoft.com> wrote in message
news:D0154070-69BB-4B78-B4C3-032C0552A4C6@microsoft.com...
> I'm using a formula to sum values in cells corresponding to time slots in
the
> day such as 08:00, 08:15 etc and have produced a macro to extract these
> timeslots prior to using the formula.
>
> Some of the source data, however, has errors and occasionally an
additional
> time slot will appear e.g. 08:00 where in fact 08:15 should be.
>
> In order to accurately produce an error-free summary of the values at each
> time slot I realise that VLookup could do what I want, but I'm not sure
> exactly how to write the formula.
>
> For example, if the data on my sheet was as follows:
>
> Monday 3/1/05 08:15 456 (cell ref: F105)
> Monday 10/1/05 08:15 789 (cell ref: F469) etc etc
>
> and I wanted to sum 456 and 789 and all other values for 08:15 for January
'05
>
> 1. what VLookup formula would I use to achieve this?
> 2. How would I then copy tis new total to a summary table in another sheet
> on this Workbook?
>