cstime provides date
and time functions for public health surveillance. Its main purpose is
consistent conversion between:
- Date.
- Isoyear, isoweek, isoyearweek.
- Season week.
It also provides functions to generate rolling date ranges for
computing weekly, bi-weekly, and 4-week averages.
cstime is part of the csverse package
suite.
library(cstime)
#> cstime 2025.10.13
#> https://niphr.github.io/cstime/
library(magrittr)
Date to isoyear
date_to_isoyear_c('2021-01-01')
#> [1] "2020"
Isoyearweek string to isoyear and isoweek
isoyearweek_to_isoyear_c("2021-02")
#> [1] "2021"
isoyearweek_to_isoweek_c("2021-02")
#> [1] "02"
Season week and isoweek
seasonweek_to_isoweek_n(10)
#> [1] 44
isoweek_to_seasonweek_n(1)
#> [1] 19