This function identifies the epidemiological season to which a given date belongs. The epidemiological season is defined by a start and end week, where weeks are numbered according to the ISO week date system.
Arguments
- date
A date object representing the date to check.
- start
An integer specifying the start week of the epidemiological season.
- end
An integer specifying the end week of the epidemiological season.
Value
A character vector indicating the season:
"out_of_season" if the date is outside the specified season,
If within the season, the function returns a character string indicating the epidemiological season.
Examples
# Check if a date is within the epidemiological season
epi_calendar(as.Date("2023-09-15"), start = 40, end = 20)
#> [1] "out_of_season"
# Expected output: "2022/2023"
epi_calendar(as.Date("2023-05-01"), start = 40, end = 20)
#> [1] "2022/2023"
# Expected output: "out_of_season"
epi_calendar(as.Date("2023-01-15"), start = 40, end = 20)
#> [1] "2022/2023"
# Expected output: "2022/2023"
epi_calendar(as.Date("2023-12-01"), start = 40, end = 20)
#> [1] "2023/2024"
# Expected output: "2023/2024"