Ops Group Method for Date/Time Objects

Ops.Date

Description

The group method defining mathematical operations on date/time objects.

Usage

## Date
Date Compare Date   -> logical
+ Date              -> Date
Date - Date         -> difftime
Date + numeric      -> Date
Date - numeric      -> Date
Date + difftime     -> Date
Date - difftime     -> Date
numeric + Date      -> Date
difftime + Date     -> Date
## POSIXt
POSIXt Compare POSIXt   -> logical
+ POSIXt                -> POSIXt
POSIXt - POSIXt         -> difftime
POSIXt + numeric        -> POSIXt
POSIXt - numeric        -> POSIXt
POSIXt + difftime       -> POSIXt
POSIXt - difftime       -> POSIXt
numeric + POSIXt        -> POSIXt
difftime + POSIXt       -> POSIXt
## difftime
difftime Compare difftime   -> logical
+ difftime                  -> difftime
- difftime                  -> difftime
difftime + difftime         -> difftime
difftime - difftime         -> difftime
difftime + numeric          -> difftime
difftime - numeric          -> difftime
numeric + difftime          -> difftime
numeric - difftime          -> difftime
difftime * numeric          -> difftime
difftime / numeric          -> difftime
numeric * difftime          -> difftime

Arguments

Date	a Date object.
POSIXt	a POSIXt object.
difftime	a difftime object.
numeric	a numeric object.
logical	a logical object.
Compare	a logic operator including "<", ">", "!=", "==", "<=" and ">=".

Details

For operations involving both Date and numeric, the numeric is treated as the number of days.
For operations involving both POSIXt and numeric, the numeric is treated as the number of seconds.
For operations involving both difftime and numeric, the numeric is treated as the number of units of the difftime object.

Value

an object as described in the usage section.

See Also

Date, POSIXt, difftime, Ops

Examples

## Date
as.Date("2038-01-19") > as.Date("1970-01-01")
as.Date("2038-01-19") - as.Date("1970-01-01")
as.Date("1970-01-01") + (as.Date("2038-01-19") - as.Date("1970-01-01"))
as.Date("1970-01-01") + 1
as.Date("1970-01-01") + as.difftime(1, units = "weeks")
## POSIXt
as.POSIXct("2038-01-19 03:14:07") > as.POSIXct("1970-01-01 00:00:00")
as.POSIXct("2038-01-19 03:14:07") - as.POSIXct("1970-01-01 00:00:00")
as.POSIXct("1970-01-01 00:00:00") + (2^31 - 1)
as.POSIXct("1970-01-01 00:00:00") + 1
as.POSIXct("1970-01-01 00:00:00") + as.difftime(1, units = "weeks")
## difftime
(df1 <- as.difftime(12, units = "hours"))
(df2 <- as.difftime(1, units = "days"))
df1 * 2 == df2
df1 + 12
df2 / 2

Package base version 6.1.4-13
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