Convert rainfall data from 10 minutes to 20 min,30 min,1 hr ..

i have rainfall data every 10 min and i need to find from this data the rainfall every 20 min , 30 min ,1 hr ets
my data here
data.xlsx
10
DT RD
10/29/2004 0:00 0
10/29/2004 0:10 0
10/29/2004 0:20 0
10/29/2004 0:30 0
10/29/2004 0:40 0
10/29/2004 0:50 0
10/29/2004 1:00 0
10/29/2004 1:10 0
10/29/2004 1:20 0
10/29/2004 1:30 0
10/29/2004 1:40 0
10/29/2004 1:50 0
10/29/2004 2:00 0
10/29/2004 2:10 0
10/29/2004 2:20 0
10/29/2004 2:30 0

please help me