Hello
I have dataframes.
mydata1 <-data.frame(value=c(15,20,25,30,45,50),dates=c("2005-05-25 07:00:00
","2005-05-25 19:00:00","2005-06-25 07:00:00","2005-06-25 19:00:00
","2005-07-25 07:00:00","2005-8-25 19:00:00"))
or
mydata2 <-data.frame(value=c(15,20,25,30,45,50),dates=c("2005-05-25 00:00:00
","2005-05-25 00:10:00","2005-05-25 00:30:00","2005-05-25 00:40:00
","2005-05-25 00:50:00","2005-5-25 01:10:00"))

I have to get  such dataframes

mydata1 <-data.frame(value=c(15,20,25,30,45,NA,NA,50),dates=c("2005-05-25
07:00:00","2005-05-25 19:00:00","2005-06-25 07:00:00","2005-06-25 19:00:00
","2005-07-25 07:00:00","2005-07-25 19:00:00","2005-8-25 07:00:00",
"2005-8-25 19:00:00"))
or
mydata2 <-data.frame(value=c(15,20,NA,25,30,45,NA,50),dates=c("2005-05-25
00:00:00","2005-05-25 00:10:00","2005-05-25 00:20:00","2005-05-25 00:30:00
","2005-05-25 00:40:00","2005-05-25 00:50:00","2005-5-25 01:00:00",
"2005-5-25 01:10:00"))

Regards, Aleksander.

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