I have two R objects, allDataSubset1 and allDataSubset2 and the str of both of them is shown below ( I don't show all 18 lists for space purposes ). The difference between them is that the times ( and possibly the days ) and the data is different and what I want to do is merge them so that only the data in Subset2 that is the same day and times as Subset 1 remains in the merged dataset. Obviously the column names of Subset2 would have to changed to AUDB, CADB, CHFB etc when they were merged ? I have no idea how to do this and originally these 2 lists come from a zoo object so , if it's easier to merge the zoo objects and then do the creation of the lists, that's okay also but I don't know how to do that either. So, if someone wants me to send the the str of the zoo objects, I can do that also. Thanks so much for any help on this. It seems really complicated to me and I looked up merge but it said that it works off of data frames ? Maybe I need to put them in a data frame but with all these lists of lists etc, I'm totally clueless on how to do that. [1] "STR OF allDataSubset1" List of 18 $ 20050101: num [1:2565, 1:7] 20050103 20050103 20050103 20050103 20050103 ... ..- attr(*, "dimnames")=List of 2 .. ..$ : NULL .. ..$ : chr [1:7] "filedate" "AUD" "CAD" "CHF" ... ..- attr(*, "index")='POSIXct', format: chr [1:2565] "2005-01-03 08:04:00" "2005-01-03 08:08:00" "2005-01-03 08:12:00" "2005-01-03 08:16:00" ... $ 20050201: num [1:2430, 1:7] 20050201 20050201 20050201 20050201 20050201 ... ..- attr(*, "dimnames")=List of 2 .. ..$ : NULL .. ..$ : chr [1:7] "filedate" "AUD" "CAD" "CHF" ... ..- attr(*, "index")='POSIXct', format: chr [1:2430] "2005-02-01 08:04:00" "2005-02-01 08:08:00" "2005-02-01 08:12:00" "2005-02-01 08:16:00" ... $ 20050301: num [1:2970, 1:7] 20050301 20050301 20050301 20050301 20050301 ... ..- attr(*, "dimnames")=List of 2 .. ..$ : NULL .. ..$ : chr [1:7] "filedate" "AUD" "CAD" "CHF" ... ..- attr(*, "index")='POSIXct', format: chr [1:2970] "2005-03-01 08:04:00" "2005-03-01 08:08:00" "2005-03-01 08:12:00" "2005-03-01 08:16:00" ... $ 20050401: num [1:2835, 1:7] 20050401 20050401 20050401 20050401 20050401 ... #====================================================================================================================================== List of 18 $ 20050101: num [1:10260, 1:7] 20050103 20050103 20050103 20050103 20050103 ... ..- attr(*, "dimnames")=List of 2 .. ..$ : NULL .. ..$ : chr [1:7] "filedate" "AUD" "CAD" "CHF" ... ..- attr(*, "index")='POSIXct', format: chr [1:10260] "2005-01-03 08:01:00" "2005-01-03 08:02:00" "2005-01-03 08:03:00" "2005-01-03 08:04:00" ... $ 20050201: num [1:9720, 1:7] 20050201 20050201 20050201 20050201 20050201 ... ..- attr(*, "dimnames")=List of 2 .. ..$ : NULL .. ..$ : chr [1:7] "filedate" "AUD" "CAD" "CHF" ... ..- attr(*, "index")='POSIXct', format: chr [1:9720] "2005-02-01 08:01:00" "2005-02-01 08:02:00" "2005-02-01 08:03:00" "2005-02-01 08:04:00" ... $ 20050301: num [1:11880, 1:7] 20050301 20050301 20050301 20050301 20050301 ... ..- attr(*, "dimnames")=List of 2 .. ..$ : NULL .. ..$ : chr [1:7] "filedate" "AUD" "CAD" "CHF" ... ..- attr(*, "index")='POSIXct', format: chr [1:11880] "2005-03-01 08:01:00" "2005-03-01 08:02:00" "2005-03-01 08:03:00" "2005-03-01 08:04:00" ... $ 20050401: num [1:11340, 1:7] 20050401 20050401 20050401 20050401 20050401 ... ..- attr(*, "dimnames")=List of 2 .. ..$ : NULL .. ..$ : chr [1:7] "filedate" "AUD" "CAD" "CHF" ... ..- attr(*, "index")='POSIXct', format: chr [1:11340] "2005-04-01 08:01:00" "2005-04-01 08:02:00" "2005-04-01 08:03:00" "2005-04-01 08:04:00" ... -------------------------------------------------------- This is not an offer (or solicitation of an offer) to buy/se...{{dropped}}