R: 2 functions with the same name in 2 different packages

library(chron)
is.weekend.chron <- is.weekend
library(tseries)

then you can call is.weekend for the tseries version or is.weekend.chron for the chron version

You have probably already noticed that the order of loading the packages makes a difference, i.e. the package that gets loaded last will mask the functions in packages loaded earlier.

To specify the package that you want to use, the syntax is:

chron::is.weekend()
tseries::is.weekend()

In other words, use packagename::functionname()

In addition, if you know that you will always want to use the function in chron, you can define your own function as follows:

is.weekend <- chron::is.weekend    #EDIT