Lubridate provides ymd()
series of functions for parsing character strings into dates. The letters y, m, and d correspond to the year, month, and day elements of a date-time.
mdy("07-21-2016") # Returns Date
## [1] "2016-07-21"
mdy("07-21-2016", tz = "UTC") # Returns a vector of class POSIXt
## "2016-07-21 UTC"
dmy("21-07-2016") # Returns Date
## [1] "2016-07-21"
dmy(c("21.07.2016", "22.07.2016")) # Returns vector of class Date
## [1] "2016-07-21" "2016-07-22"