First day of the month from a POSIXct date time using lubridate

Question

Given a POSIXct date time, how do you extract the first day of the month for aggregation?

library(lubridate)

full.date <- ymd_hms(\"2013-01-01 00:00:21\"         


        

Answer 1

i have another solution :

first.of.month <- full.date - mday(full.date) + 1

but it needs the library 'lubridate' or 'date.table'(aggregation with data.table)