Can anyone tell me what formula i could use to perform a function
whenever for example,the month of April or perhaps the 31 days of a
specific month appears in the data.


For example,below is 3 columns and if you imagine that the time column
extends to
a full year.
Time x values Y values
15/02/2008 17:15 1590158.49 9.12
15/02/2008 17:30 1590168.64 10.15
15/02/2008 17:45 1590178.3 9.66
15/02/2008 18:00 1590187.91 9.61
15/02/2008 18:15 1590197.4 9.49
What i want to do is if the first column contains the month of feb
then add the corresponding x and y values
IE taking the first line, the first column does represent a day in
Feb
so add 1590158.49 and 9.12 which will produce 1590167.61

I would be most grateful for any help.
Thanks
David