cast string directly to IDateTime

Question

I am using the new version of data.table and especially the AWESOME fread function. My files contain dates that are loaded as strings (cause I don\

Answer 1

I d'ont know how your file is structured, but from your comment you want to use the date field as a key. Why not to read it as a time series and format it when in reading?

Here I use zoo to do it.(Here I suppose that the date column is the first one,otherwise see index.colum argument)

ff <- function(x) as.POSIXct(strptime(x,"%d%b%Y:%H:%M:%S"))

h <- read.zoo(text = "03avril2008:09:00:00  125
                      02avril2008:09:30:00  126
                      05avril2008:09:10:00  127
                      04avril2008:09:20:00  128
                      01avril2008:09:00:00  128"
                      ,FUN=ff)

You get your dates sorted in the right format and sorted.

The conversion is natural from POSIXct to IDateTime

    IDateTime(index(h))
        idate    itime
1: 2008-04-01 09:00:00
2: 2008-04-02 09:30:00
3: 2008-04-03 09:00:00
4: 2008-04-04 09:20:00
5: 2008-04-05 09:10:00

Here sure you still do 2 conversions, But you do it when reading data, and the second you do it without dealing with any format problem.