如果向量組件之間的時間大于x，則拆分日期時間向量

你可以用

library(dplyr)

df %>% 
  mutate(cat = 1 + cumsum(c(0, diff(times)) > 5))

which returns

   index               times cat
1      1 2020-10-03 21:31:00   1
2      2 2020-10-03 21:32:00   1
3      3 2020-10-03 21:33:00   1
4      4 2020-10-03 21:34:00   1
5      5 2020-10-03 21:35:00   1
6      6 2020-10-03 21:36:00   1
7      7 2020-10-03 21:37:00   1
8      8 2020-10-03 21:38:00   1
...
53    53 2020-10-03 22:23:00   1
54    54 2020-10-03 22:24:00   1
55    55 2020-10-03 22:25:00   1
56    56 2020-11-03 10:10:00   2
57    57 2020-11-03 10:11:00   2
58    58 2020-11-03 10:12:00   2
59    59 2020-11-03 10:13:00   2

如果你需要字母或其他東西，你可以使用

df %>% 
  mutate(cat = LETTERS[1 + cumsum(c(0, diff(times)) > 5)])

將類別1和2轉換為A和B。