is_start_day() checks whether x is the start or end of a day.
is_mid_day() checks whether x is the middle of a day.
These properties are not necessarily preserved when a duration of n years is added or subtracted.
Value
A vector of logical. Elements of the datey vector that are
NA_datey_ will result in NA elements of the result vector.
Examples
# Create (NA, 0 days, 1/4 day, 1/2 day):
t <- datey(c(NA_real_, 2000, 2000 + 0.25/366, 2000 + 0.5/366))
t # <NA> 2000-01-01.0 2000-01-01.25 2000-01-01.5
#> [1] <NA> 2000-01-01.0 2000-01-01.25 2000-01-01.5
is_start_day(t) # NA TRUE FALSE FALSE
#> [1] NA TRUE FALSE FALSE
is_mid_day(t) # NA FALSE FALSE TRUE
#> [1] NA FALSE FALSE TRUE
# Properties are not necessarily preserved between years:
t <- start_day(2000,7,1) # Leap year
is_start_day(t) # TRUE
#> [1] TRUE
is_start_day(t + durationy(1)) # FALSE
#> [1] FALSE