For data with date-times YYYYMMDDTHHZ,
1) category mode just outputs year, month, date -- hour information is not output, and only the hour=0 data are output
2) in series mode, what is output is YYYY MMDDTHHZ DD, e.g., 2018 0731T10Z 31; the more useful output is YYYY MM DD HH
For data with date-times YYYYMMDDTHHZ, 1) category mode just outputs year, month, date -- hour information is not output, and only the hour=0 data are output 2) in series mode, what is output is YYYY MMDDTHHZ DD, e.g., 2018 0731T10Z 31; the more useful output is YYYY MM DD HH