Handling dates when we switch to daylight savings time and back

Question

I would like to use R for time series analysis. I want to make a time-series model and use functions from the packages timeDate and forecast.

I have intraday data in

Answer 1

Here is getting the daylight savings time offset - e.g. Central Daylight Savings time

> Sys.time()

"2015-08-20 07:10:38 CDT" # I am at America/Chicago daylight time

> as.POSIXct(as.character(Sys.time()), tz="America/Chicago")

"2015-08-20 07:13:12 CDT"

> as.POSIXct(as.character(Sys.time()), tz="UTC") - as.POSIXct(as.character(Sys.time()), tz="America/Chicago")

Time difference of -5 hours

> as.integer(as.POSIXct(as.character(Sys.time()), tz="UTC") - as.POSIXct(as.character(Sys.time()), tz="America/Chicago"))

-5

Some inspiration was from

Converting time zones in R: tips, tricks and pitfalls