R Labeling multiple date periods in a POSIXlt date sequence

Question

I am working in R. I have a date sequence and I would like assign whether each particular date is term time or a school holiday. I plan to do this using a dataframe column where each row is labelled "Holiday" or "Term"

My approach is to create a time sequence and individually specify each holiday dates using a vector; the first element is the start date of the holiday and the second is the end of the holiday.

I then create an if-or statement to test whether the time lies within any of the holiday dates specified in the vectors.

Here is my code so far:

start <- as.POSIXlt("2015-10-10 00:00:00")
end <- as.POSIXlt("2016-03-31 00:00:00")

DateSeq <- seq(from=start, to=end, by="mins")

#Holidays defined using a vector with by start and end date

H1 <- c("2015-10-26", "2015-11-3") #October half term
H2 <- c("2015-12-16", "2016-01-05") #Christmas holiday
H3 <- c("2016-02-15", "2016-02-19") #Feb half term 
H4 <- c("2016-03-24", "2016-03-31") #Easter holiday 

date_table <- data.frame(Time = DateSeq)

if ((round(date_table$Time, units = "days")== H1[1] <> H1[2]) |         (round(date_table$Time, units = "days") == H2[1] <> H2[2])) {
  date_table$Holiday <- "Holiday"
 } else {
  date_table$Holiday <- "Term"
}

As you can see this code does not work and simply labels all the rows as "Term".

Therefore I am wondering the following:

1. How I can specify the date range in the holiday vectors so it can be used within the if statement?

2. Whether this is the best approach to use? I am quite new to R and I was thinking of alternatives such as creating a set of individual sequences for term and holidays and then stitching them together. This approach however seems fiddly but would appreciate your thoughts.

Thanks for your help.

Answer 1

Similar to your approach by avoid if-else.

# Or alternatively by="mins"
DateSeq <- seq(from=start, to=end, by="hours")
date_table <- data.frame(Time = DateSeq)

# Put all holidays together
H<-rbind(H1,H2,H3,H4)

# Or alternatively set to "Term"
date_table$Holiday<-0

# Assign all the holidays
for (i in 1:nrow(H)){
  date_table[date_table$Time > H[i,1] &  date_table$Time < H[i,2],"Holiday"]<-1 # or "Holiday"
}

# Check they are correctly assign
plot(date_table)

Answer 2

You could use cut() to cut DateSeq into term and holiday.

res <- cut(DateSeq, breaks = as.POSIXlt( c(H1, H2, H3, H4), format = "%Y-%m-%d"), labels = c("October", "term1", "Christmas", "term2", "Feb", "Term3", "Easter"))
table(res)