How to sort a data frame by date

Assuming your data frame is named d,

d[order(as.Date(d$V3, format="%d/%m/%Y")),]

Read my blog post, Sorting a data frame by the contents of a column, if that doesn't make sense.

Nowadays, it is the most efficient and comfortable to use lubridate and dplyr libraries.

lubridate contains a number of functions that make parsing dates into POSIXct or Date objects easy. Here we use dmy which automatically parses dates in Day, Month, Year formats. Once your data is in a date format, you can sort it with dplyr::arrange (or any other ordering function) as desired:

d$V3 <- lubridate::dmy(d$V3)
dplyr::arrange(d, V3)