[R] Day or Month difference between dates???

[Rui Barradas]

Hello,

Try

library(zoo) # needed for as.yearmon

x <- c(201009, 201010, 201011, 201101, 201102)
(y <- as.Date(paste(x, "01", sep=""), format="%Y%m%d"))
y - y[1]
12*(as.yearmon(y) - as.yearmon(y[1]))

Note that to have a time difference between dates we need days (paste).

Hope this helps,

Rui Barradas

Em 01-06-2012 12:31, Tammy Ma escreveu:
> HI, R-Users:
>
> I got a questions. have been struggling so long time....
>
> I have this data:
>
>> m1$Year_Month
>    201009 201010 201011 201101 201102
>> min(m1$Year_Month)
>    201009
>
> I want to calculate the following two answers, how do I program it?
>
>> difference in Month?????
>   [1] 0 1 2 4 5
>
>> difference in Days?????
>   0  31  61 ....
>
> Thank you in advance!!!
>
> Tammy
>   		 	   		
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