x <- seq.Date(as.Date("2009-08-02"), by = "year", length.out = 2)
# "2009-08-02" "2010-08-02"
pretty_dates(x, 12)
## [1] "2009-08-01 GMT" "2009-09-01 GMT" "2009-10-01 GMT" "2009-11-01 GMT"
## [5] "2009-12-01 GMT" "2010-01-01 GMT" "2010-02-01 GMT" "2010-03-01 GMT"
## [9] "2010-04-01 GMT" "2010-05-01 GMT" "2010-06-01 GMT" "2010-07-01 GMT"
## [13] "2010-08-01 GMT" "2010-09-01 GMT"
Run the code above in your browser using DataCamp Workspace