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WEEL Guide

8 Date times

8.1 parsedate

If you need to set the tz of the incoming data - an option is parsedate. Similarly flexible than anytime, but allows the input tz to be specified a bit easier. Internally, dates are always stored as UTC, with the timezone attribute helping to print the times in the specified time zone. On this day, 14:00 NL time = 17:30 UTC and 14:00 BC time = 22:00 UTC.

library(parsedate)
times <- c("2004-03-01 14:00:00",
           "2004/03/01 14:00:33.123456",
           "20040301 140033.123456",
           "03/01/2004 14:00:33.123456",
           "03-01-2004 14:00:33.123456")
parse_date(times, default_tz = 'America/St_Johns')
#>  [1] "2004-03-01 17:30:00 UTC" "2004-03-01 17:30:33 UTC"
#>  [3] "2004-03-01 17:30:33 UTC" "2004-03-01 17:30:33 UTC"
#>  [5] "2004-03-01 17:30:33 UTC" 

parse_date(times, default_tz = 'America/Vancouver')
#>  [1] "2004-03-01 22:00:00 UTC" "2004-03-01 22:00:33 UTC"
#>  [3] "2004-03-01 22:00:33 UTC" "2004-03-01 22:00:33 UTC"
#>  [5] "2004-03-01 22:00:33 UTC"

A nice, less sensitive to typos, way of setting a tz might be something like this

grep('Vancouver', OlsonNames(), value = TRUE)
[1] "America/Vancouver"

> grep('Newfoundland', OlsonNames(), value = TRUE)
[1] "Canada/Newfoundland"

> grep('Hawaii', OlsonNames(), value = TRUE)
[1] "US/Hawaii"