[R] Count observation based on hour

[arun]

Hi,
Try:

data.frame(table(dat$Date))
A.K.


Hi guys, I have some 20,000 observations like this: 
          Date       
2014-01-01 00:00:00 
2014-01-02 11:00:00 
2014-01-02 22:00:00 
2014-01-03 03:00:00 

I want to perform an hourly count (e.g. the frequency occur at 
each hour for a specific date) so the result would look like this: 

          Date                    Frequency 
2014-01-01 00:00:00             1 
2014-01-01 01:00:00             1 
2014-01-01 02:00:00             1 
2014-01-01 03:00:00             1 

Any suggestions?  Thanks!