Dealing with Dates in R

To convert a character object into a date format, use the as.POSIXlt() function. This takes two arguments, the character object and a format specifying the date format as represented in the character object.

So if we have something like

char <- "9/21/2018 17:22"
date <- as.POSIXlt(char,format="%m/%d/%Y %H:%M")

And, to extract dates from the date object we can use the format function.

day <- format(date,"%d")
hour <- format(date,"%H")

Note: If you are going to work with the dplyr package, you might get an error saying Column Date is of unsupported class POSIXlt/POSIXt, just use as.POSIXct() instead and it will work fine.