Ruslan,

Use a Pivot table - Select your data, use Data | Pivot Table. Then drag
"Data" to the row filed area, and "Amounts" to the data area. Then on the
Pivot Table commandbar, select the pivot table dropdown, then choose "Group
and Show detail" then choose Group, and select the month option, and Excel
will automatically sum your data (or average, or show max, or min, etc.) by
month. No formulas. Ever.

HTH,
Bernie
MS Excel MVP

"Ruslan" wrote in message
...
Dear All,
I have the following data:

Data Amounts

01.01.05 1000
02.01.05 2000
10.01.05 14000
01.02.05 3000
12.02.05 2500
... etc. ..etc.

I need to calculate the sum of all amounts in january, february, march,
etc...separately....
in other words, ...if data is within january then sum of january's amounts
and so on...
I appreciate you help in advance,
Ruslan