title: About chron time matching in r
body: <p>I try to match two files by using the time column in r. Therefore, I choose chron time to achieve this. But when I try to convert the 'Time' column to chron time, I got the warning message that 'In convert.dates(dates., format = format[[1]], origin. = origin.): 331 months out of range set to NA'
  my data are as follows,</p>
  <pre><code>  Year Month Day Rain_mm                Time           chrontime
  1   2019     1   1     0.6 01/01/2019 01:10:00 (01/01/19 01:10:00)
  2   2019     1   2     0.0 02/01/2019 01:10:00 (02/01/19 01:10:00)
  3   2019     1   3     0.0 03/01/2019 01:10:00 (03/01/19 01:10:00)
  4   2019     1   4     0.0 04/01/2019 01:10:00 (04/01/19 01:10:00)
  5   2019     1   5     0.0 05/01/2019 01:10:00 (05/01/19 01:10:00)
  6   2019     1   6     0.0 06/01/2019 01:10:00 (06/01/19 01:10:00)
  7   2019     1   7     3.4 07/01/2019 01:10:00 (07/01/19 01:10:00)
  8   2019     1   8     5.8 08/01/2019 01:10:00 (08/01/19 01:10:00)
  9   2019     1   9     0.4 09/01/2019 01:10:00 (09/01/19 01:10:00)
  10  2019     1  10     0.0 10/01/2019 01:10:00 (10/01/19 01:10:00)
  11  2019     1  11     0.2 11/01/2019 01:10:00 (11/01/19 01:10:00)
  12  2019     1  12     2.8 12/01/2019 01:10:00 (12/01/19 01:10:00)
  13  2019     1  13     2.6 13/01/2019 01:10:00             (NA NA)
  14  2019     1  14     2.2 14/01/2019 01:10:00             (NA NA)
  15  2019     1  15     3.2 15/01/2019 01:10:00             (NA NA)
  16  2019     1  16     6.2 16/01/2019 01:10:00             (NA NA)
  17  2019     1  17    12.6 17/01/2019 01:10:00             (NA NA)
  18  2019     1  18     0.0 18/01/2019 01:10:00             (NA NA)
  19  2019     1  19     0.0 19/01/2019 01:10:00             (NA NA)
  20  2019     1  20     0.0 20/01/2019 01:10:00             (NA NA)
  21  2019     1  21     7.4 21/01/2019 01:10:00             (NA NA)
  22  2019     1  22     0.2 22/01/2019 01:10:00             (NA NA)
  23  2019     1  23     0.0 23/01/2019 01:10:00             (NA NA)
  24  2019     1  24     0.0 24/01/2019 01:10:00             (NA NA)
  25  2019     1  25     0.0 25/01/2019 01:10:00             (NA NA)
  26  2019     1  26     0.6 26/01/2019 01:10:00             (NA NA)
  27  2019     1  27     7.6 27/01/2019 01:10:00             (NA NA)
  28  2019     1  28     1.6 28/01/2019 01:10:00             (NA NA)
  29  2019     1  29     0.0 29/01/2019 01:10:00             (NA NA)
  30  2019     1  30     0.0 30/01/2019 01:10:00             (NA NA)
  31  2019     1  31     0.0 31/01/2019 01:10:00             (NA NA)
  32  2019     2   1     0.0 01/02/2019 01:10:00 (01/02/19 01:10:00)
  33  2019     2   2     0.6 02/02/2019 01:10:00 (02/02/19 01:10:00)
  34  2019     2   3     0.0 03/02/2019 01:10:00 (03/02/19 01:10:00)
  35  2019     2   4     1.0 04/02/2019 01:10:00 (04/02/19 01:10:00)
  36  2019     2   5     0.2 05/02/2019 01:10:00 (05/02/19 01:10:00)
  37  2019     2   6     3.6 06/02/2019 01:10:00 (06/02/19 01:10:00)
  38  2019     2   7     1.8 07/02/2019 01:10:00 (07/02/19 01:10:00)
  39  2019     2   8     3.0 08/02/2019 01:10:00 (08/02/19 01:10:00)
  40  2019     2   9     6.8 09/02/2019 01:10:00 (09/02/19 01:10:00)
  41  2019     2  10     3.4 10/02/2019 01:10:00 (10/02/19 01:10:00)
  42  2019     2  11     0.6 11/02/2019 01:10:00 (11/02/19 01:10:00)
  43  2019     2  12     0.0 12/02/2019 01:10:00 (12/02/19 01:10:00)
  44  2019     2  13     0.0 13/02/2019 01:10:00             (NA NA)
  45  2019     2  14     0.0 14/02/2019 01:10:00             (NA NA)
  46  2019     2  15     0.0 15/02/2019 01:10:00             (NA NA)
  ......
  </code></pre>
  <p>my codes are:</p>
  <pre><code>Dts &lt;- with(DMIdata, paste(substring(Time, 1,2), substring(Time,4,5), substring(Time, 9, 10), sep='/'))    
  hrs &lt;- with(DMIdata, substring(Time, 13, 20))
  DMIdata$chrontime &lt;- chron(Dts,hrs)
  </code></pre>
  <p>I was wondering why all the dates after the 13th are set to NA in the chronic transformation? And how to improve my codes to make it work?</p>
  <p>Thanks for any help!</p>