获取as.Date的缩写月份格式的NA

# 示例代码
dates <- c("2023-01-01", "2023-02-01", "not a date")
parsed_dates <- as.Date(dates, format = "%Y-%m-%d")

# 检查 NA 值
na_values <- is.na(parsed_dates)
print(na_values)  # 输出哪些值是 NA

# 手动解析日期
manual_parsed_dates <- strptime(dates, format = "%Y-%m-%d", tz = "UTC")
print(manual_parsed_dates)

Sys.setenv(TZ = "UTC")  # 设置时区为 UTC

Sys.setlocale("LC_TIME", "en_US.UTF-8")  # 设置语言环境为英文

# 示例代码
dates <- c("2023-01-01", "2023-02-01", "2023-03-01")
parsed_dates <- as.Date(dates, format = "%Y-%m-%d")

# 获取缩写月份格式
abbrev_month <- format(parsed_dates, "%b")
print(abbrev_month)  # 输出 "Jan" "Feb" "Mar"