2371727
format一下即可,不过记得核对一下时间是不是正确,
a = 0:20
# tmp <- strptime(a, format = "%j")
# lubridate::parse_date_time()
tmp <- as.Date(a, format = "%j",origin = lubridate::origin)
month_day <- format(tmp, format = "%m-%d")
data.frame(a,month_day)
#> a month_day
#> 1 0 01-01
#> 2 1 01-02
#> 3 2 01-03
#> 4 3 01-04
#> 5 4 01-05
#> 6 5 01-06
#> 7 6 01-07
#> 8 7 01-08
#> 9 8 01-09
#> 10 9 01-10
#> 11 10 01-11
#> 12 11 01-12
#> 13 12 01-13
#> 14 13 01-14
#> 15 14 01-15
#> 16 15 01-16
#> 17 16 01-17
#> 18 17 01-18
#> 19 18 01-19
#> 20 19 01-20
#> 21 20 01-21
Created on 2018-10-23 by the reprex package (v0.2.1)