cómo encontrar todas las fechas faltantes e incrementar la serie en r

# Date padding is implemented in the padr package in R. If you store your data frame, with your date-time variable stored as POSIXct or POSIXlt. All you need to do is:

library(padr)
pad(df_name)

# See vignette("padr") or this blog post for its working.
Worrisome Wombat