seq.dates(from, to, by = "days", length.out, k.by = 1)
dates object,
an integer representing a Julian date, or a character string of the
form
"mm/dd/yy", for example
"05/23/91".
from. One of
to or
from or both
needs to be specified.
"days",
"weekdays",
"weeks",
"months",
"quarters" or
"years" giving the desired time units of
the intervals between dates. Default is one day.
by argument.
This is ignored if
by is numeric or
by="weekdays".
from and
to separated by
k.by
time units as defined by the argument
by.
The origin of the sequence will be the same as
origin(from) or
origin(to).
by="weekdays", all the weekdays between
from and
to are generated.
At least one of
from or
to is required plus
length.out, the desired
length of the resulting sequence; or both
from and
to in which case
length.out
gets ignored if supplied.
For
by="weekdays", if given
from (or
to) is a weekend, the next
Monday (or the last Friday) is used as the start (or end).
seq.dates("01/01/92", "12/31/92", by="months")
# Produces:
# [1] 01/01/92 02/01/92 03/01/92 04/01/92 05/01/92 06/01/92
# [7] 07/01/92 08/01/92 09/01/92 10/01/92 11/01/92 12/01/92
quarters1 <- seq.dates("01/01/92", "12/31/92", by="quarters")
quarters2 <- seq.dates("01/01/92", "12/31/92",by="months",k=3)
all(quarters1 == quarters2)
end.of.the.month <- seq.dates("02/29/92", by="months", length=15)
end.of.the.month
# Produces:
# [1] 02/29/92 03/31/92 04/30/92 05/31/92 06/30/92 07/31/92
# [7] 08/31/92 09/30/92 10/31/92 11/30/92 12/31/92 01/31/93
# [13] 02/28/93 03/31/93 04/30/93