Mathematical operations with 'timeDate' objects

Functions for mathematical and logical operations on "timeDate" objects.

Usage

# S4 method for class 'timeDate,timeDate'
Ops(e1, e2)

Arguments

e1, e2

objects of class "timeDate". In the case of addition and subtraction one of them may be of class numeric, specifying the number of seconds to add or subtract.

Details

Group "Ops" represents the binary mathematical operators. Methods are defined for such operations when one or both arguments are from class "timeDate".

Operations that don't make sense, such as addition of two "timeDate" objects, throw error.

The plus operator "+" performs arithmetic "+" operation on "timeDate" objects,

and the minus operator "-" returns a difftime object if both arguments e1 and e2 are "timeDate" objects, or returns a "timeDate" object e2 seconds earlier than e1.

Value

addition of numeric to "timeDate" returns "timeDate",

subtraction of numeric from "timeDate" returns "timeDate",

subtraction of two "timeDate" objects returns "difftime",

other operations between two "timeDate" objects are applied to the underlying times (slot "Date"). The result of that operation is converted to "timeDate" if it represents a time and returned as is otherwise.

Examples

## create some data
dts <- c("1989-09-28", "2001-01-15", "2004-08-30", "1990-02-09")
tms <- c(  "23:12:55",   "10:34:02",   "08:30:00",   "11:18:23")
GMT <- timeDate(dts, zone = "GMT", FinCenter = "GMT")
ZUR <- timeDate(dts, zone = "GMT", FinCenter = "Europe/Zurich")
   
## add one day 
GMT + 24*3600
#> GMT
#> [1] [1989-09-29] [2001-01-16] [2004-08-31] [1990-02-10]

## subtract
ZUR[2] - ZUR[1] 
#> Time difference of 4127 days