R: Round down dates to first day of the week

Question

I have a dataframe where one of the columns contains dates (some dates appear multiple times). I want to aggregate the dates by week. The best way I can think of this is to

Answer 1

With the week_startparameter in the floor_date function of the lubridate package you have the option to specify the beginning of the week since lubridate version 1.7.0. This allows you to perform:

library(lubridate)
dates <- seq.Date(as.Date("2016-04-04"), as.Date("2016-04-14"), by = 1)
floor_date(dates, "weeks", week_start = 1)

I would post it as a comment to Sraffa's response but I don't have the reputation.