calc_local_time: Calculate local time from UTC for US counties

Description Usage Arguments Details Value Note Examples

Description

This function inputs date-time values in Coordinated Universal Time (UTC; also known as Zulu Time), along with a vector with county Federal Information Processing Standard (FIPS) codes, and calculates the local date-time as well as the local date based on th UTC date-time.

Usage

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calc_local_time(date_time, fips, include_tz = TRUE)

Arguments

date_time

The vector of the date-time of each observation in Coordinated Universal Time (UTC). This vector can either have a POSIXct class or be a character string, with date-time given as four-digit year, two-digit month, two-digit day, two-digit hour, and two-digit minutes (with hours based on a 24-hour system). Examples of acceptable formats include, for the example of 1:00 PM Jan. 2 1999, "199901021300", "1999-01-02 13:00", and "1999/01/02 13:00".

fips

A character vector giving the 5-digit FIPS code of the county associated with each observation. This can be either a string of length 1, if all observations come from the same county, or a vector as long as the date_time vector, if different observations come from different counties.

include_tz

A TRUE / FALSE value specifying whether to include a column with the local time zone (local_tz) in the final output.

Details

This function inputs date-time values in Coordinated Universal Time (UTC; also known as Zulu Time), as well as a single value or vector of FIPS code(s) for the county associated with each observation. It returns a dataframe with columns for local date-time, local date, and, if specified, local time zone.

Value

This function returns a dataframe with columns for local date-time, local date, and, if specified, local time zone.

Note

The local time is given as a character string, rather than a POSIXct object, so that it can have different time zones for different counties within the same dataframe (i.e., if there are two counties in the dataframe that are in different time zones).

Examples

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calc_local_time(date_time = "1999-01-01 08:00", fips = "36061")

ex_datetime <- c("1999-01-01 08:00", "1999-01-01 09:00",
                 "1999-01-01 10:00")
calc_local_time(date_time = ex_datetime, fips = "36061")

ex_datetime <- c("1999-01-01 08:00", "1999-01-01 09:00",
                 "1999-01-01 10:00")
ex_fips <- c("36061", "17031", "06037")
calc_local_time(date_time = ex_datetime, fips = ex_fips)

geanders/countytimezones documentation built on May 17, 2019, 12:14 a.m.