I have a data frame which looks like this:
(我有一个数据框架，看起来像这样：)
"22:36:59", "22:37:00", "22:37:01", "22:37:02", "22:37:03", "23:47:39", "23:47:40", "23:47:41", "23:47:42", "23:47:43", "23:47:44", "23:47:45", "23:47:46", "23:47:47", "23:47:48", "23:59:49", "23:59:50", "23:59:51", "23:59:52", "23:59:53", "23:59:54", "23:59:55", "23:59:56", "23:59:57", "23:59:58", "23:59:59"), class = "factor"), V5 = structure(c(1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L), .Label = "CEST", class = "factor"), V6 = c(2019L, 2019L, 2019L, 2019L, 2019L, 2019L, 2019L, 2019L, 2019L, 2019L)), row.names = c(NA, 10L), class = "data.frame") I want to change the hours in column V4 by subtracting 07:00:00.
(“ 22:36:59”，“ 22:37:00”，“ 22:37:01”，“ 22:37:02”，“ 22:37:03”，“ 23:47:39”，“ 23 ：47：40“，” 23:47:41“，” 23:47:42“，” 23:47:43“，” 23:47:44“，” 23:47:45“，” 23:47 ：46“，” 23:47:47“，” 23:47:48“，” 23:59:49“，” 23:59:50“，” 23:59:51“，” 23:59:52 “，” 23:59:53“，” 23:59:54“，” 23:59:55“，” 23:59:56“，” 23:59:57“，” 23:59:58“， “ 23:59:59”），类=“因子”），V5 =结构（c（1L，1L，1L，1L，1L，1L，1L，1L，1L，1L），.Label =“ CEST”， class =“ factor”），V6 = c（2019L，2019L，2019L，2019L，2019L，2019L，2019L，2019L，2019L，2019L）），row.names = c（NA，10L），class =“ data.frame “）我想通过减去07:00:00来更改V4列中的小时。)
If the hours in column V4 is smaller than 07:00:00 then it should as well change the day in column V3 and in case the day goes to the month before then it should change the month in column V2.(如果V4列中的小时数小于07:00:00，则还应更改V3列中的日期，并且如果该日期到达前一个月，则应更改V2列中的月份。)
The final aim of this is to count how many rows are there for each day, for which I can use: count(entertainment_one, c("V2", "V3")) but before I need to reorganise my data frame.(这样做的最终目的是计算每天可以使用多少行：count（entertainment_one，c（“ V2”，“ V3”））但在我需要重新组织数据框之前。)
I am new to R and do not know where to start.(我是R新手，不知道从哪里开始。)
Any help would be really appreciated, thank you very much!(任何帮助将不胜感激，非常感谢！)
ask by Sofia Olivieri translate from so
