date2decyear
date2decyear(w)
dates <- as.Date(c("1996-01-01", "1999-12-31", "2004-02-29", "2005-03-01"))
date2decyear(dates)
#> [1] 1996.001 1999.999 2004.163 2005.163
decyear2date(c(1996.0014, 1999.9986, 2004.1626, 2005.1630))
#> [1] "1996-01-01" "1999-12-31" "2004-02-29" "2005-03-01"