seq.POSIXt

R Base 3.6.2

The method for seq for date-time classes.

Syntax

# S3 method for POSIXt
seq(from, to, by, length.out = NULL, along.with = NULL, &#8230;)

Arguments

Parameter	Description
`from`	starting date. Required.
`to`	end date. Optional.
`by`	increment of the sequence. Optional. See ‘Details’.
`length.out`	integer, optional. Desired length of the sequence.
`along.with`	take the length from the length of this argument.
`…`	arguments passed to or from other methods.

Return Value

A vector of class "POSIXct".

Details

by can be specified in several ways. A number, taken to be in seconds. A object of class difftime A character string, containing one of "sec", "min", "hour", "day", "DSTday", "week", "month", "quarter" or "year". This can optionally be preceded by a (positive or negative) integer and a space, or followed by "s". The difference between "day" and "DSTday" is that the former ignores changes to/from daylight savings time and the latter takes the same clock time each day. "week" ignores DST (it is a period of 144 hours), but "7 DSTdays" can be used as an alternative. "month" and "year" allow for DST. The time zone of the result is taken from from: remember that GMT means UTC (and not the time zone of Greenwich, England) and so does not have daylight savings time. Using "month" first advances th

Examples

Example

# NOT RUN {
## first days of years
seq(ISOdate(1910,1,1), ISOdate(1999,1,1), "years")
## by month
seq(ISOdate(2000,1,1), by = "month", length.out = 12)
seq(ISOdate(2000,1,31), by = "month", length.out = 4)
## quarters
seq(ISOdate(1990,1,1), ISOdate(2000,1,1), by = "quarter") # or "3 months"
## days vs DSTdays: use c() to lose the time zone.
seq(c(ISOdate(2000,3,20)), by = "day", length.out = 10)
seq(c(ISOdate(2000,3,20)), by = "DSTday", length.out = 10)
seq(c(ISOdate(2000,3,20)), by = "7 DSTdays", length.out = 4)
# }