> df <- tibble(x = as.POSIXct("2016-01-01 12:34:56 GMT") + 1:12)
> df$y <- as.POSIXlt(df$x)
> print(df, n = 8L, width = 60L)
# A tibble: 12 x 2
  x                   y                  
  <dttm>              <dttm>             
1 2016-01-01 12:34:57 2016-01-01 12:34:57
2 2016-01-01 12:34:58 2016-01-01 12:34:58
3 2016-01-01 12:34:59 2016-01-01 12:34:59
4 2016-01-01 12:35:00 2016-01-01 12:35:00
5 2016-01-01 12:35:01 2016-01-01 12:35:01
6 2016-01-01 12:35:02 2016-01-01 12:35:02
7 2016-01-01 12:35:03 2016-01-01 12:35:03
8 2016-01-01 12:35:04 2016-01-01 12:35:04
# … with 4 more rows

> x <- c("成交日期", "合同录入日期")
> df <- setNames(tibble(1:3, 4:6), x)
> print(df, n = 8L, width = 60L)
# A tibble: 3 x 2
  成交日期 合同录入日期
     <int>        <int>
1        1            4
2        2            5
3        3            6

