Checking if there exists a value in vector of dates that lies within a given range

This checks each of the two conditions and then ANDs them.

any( dates >= given_date - 150 & dates < given_date ) &
  any( dates >= given_date - 300 & dates < given_date - 150 ) 
## [1] TRUE

Update

Fixed.

We can use between in dplyr or data.table

library(dplyr)
any(between(dates, given_date - 150, given_date)) && 
   any(between(dates, given_date - 300, given_date - 150))
#[1] TRUE