Pete:

Thanks for your interest. The data from the instrument indicates a time
stamp in one column and the data in a second column. At each 10 minute
interval I want to calculate an average of the data points during that 10
minute interval. The number of data points within a 10 minute interval will
vary.

The column layout can be manipulated in excel, if that make a difference.

So I want to sort the data in time stamp sequence, then average the data in
the data column at each 10 intervals of the time stamps. I would also like to
do the same at the hour mark.

Your input would be appreciated.

--
John


"Pete_UK" wrote:

When you say "subtotal" do you mean a count of the number of items
within each time interval, or is there some other field that you want
to add up? Which column contains the time-stamps, and which column
needs to subtotalled? How many records do you have (typically)? Do you
want a separate table of time intervals and number (and if so is this
to go into another sheet)?

Pete

On Sep 18, 9:24 pm, John wrote:
In a list of data with time stamps for each data item, how can excel subtotal
the data items at 10 minute or hourly intervals. The time stamps are random
so that the number of data points within each 10 minute interval may vary.

Thanks for your help.

John