> df <- readWorksheetFromFile(file="cktime2012.xls", sheet=1)
> df$date <- ymd(df$date)
> df$time <- hms(df$time)
Warning message:
In .parse_hms(..., order = "HM", quiet = quiet) :
  Some strings failed to parse

DATEIN      TIMEIN  etc...
2012-02-01  200000  etc...
etc...

DATEIN      TIMEIN      etc...
2012-02-01  20:00:00    etc...
etc...